Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
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S udy o dynamic beha iou ia Taylo an il es and s uc u e obse a ion
o M300 ma aging s eel ab ica ed by he selec i e lase mel ing me hod
S epan Kolomy , Mi osla Jopek
*
, Jose Sedlak, Ma ek Benc, Jan Zouha
B no Uni e si y o Technology, Facul y o Mechanical Enginee ing, B no, Czech Republic
ARTICLE INFO
Keywo ds:
Ma aging s eel
Taylo an il es
Selec i e lase mel ing
Johnson–cook
High s ain a e
Mic oha dness
S uc u e
ABSTRACT
This pape deals wi h he M300 high s eng h ma aging s eel ab ica ed ia selec i e lase mel ing me hod.
Mechanical p ope ies especially mic oha dness and comp essi e yield s eng h o ma aging s eel in as-p in ed
s a e we e obse ed. The acqui ed da a was implemen ed in Johnson-Cook cons i u i e equa ion used o
nume ic simula ion, which showed he sa is ac o y co ela ion wi h he obse ed expe imen . Dynamic beha -
iou unde high s ain a e (impac eloci y eached 185 m.s
−1
) was in es iga ed ia Taylo An il Tes . The
expe imen e ealed s uc u e and geome ical changes accompanied wi h he c ea ion o cha ac e is ic unnel-
like and cylind ical a eas on he de o med sample. Impac ed sample o ehead ea u ed he inc ease o mic o-
ha dness (465 HV) accompanied wi h s uc u e changes. The s uc u e in he unnel-like a ea exhibi ed he
dec ease o a e age g ain size, which eached he minimum (3.1
μ
m) in he icini y o he impac ed o ehead.
Close analysis e ealed ha he high s ain a e caused he inc ease o high ac ion high-angle g ain bounda ies
(50,8 %) and highe geome ically necessa y disloca ion densi y (52.77 1.m
−2
) in he unnel-like a ea.
1. In oduc ion
Addi i e manu ac u ing (AM) is he p ocess o c ea ing a pa based
on a digi al model c ea ed ia Compu e Aided Design (CAD) so wa e.
In AM, ma e ial is g adually added (laye by laye ), while in machining,
ma e ial is g adually emo ed. The pa is inally o med by sin e ing
indi idual laye s o a de ined hickness, which a e s acked on op o each
o he [1]. This echnology enables p oduc ion o complex shapes ha
would no be possible o p oduce by con en ional me hods [2,3]. AM is
used and ep esen ed in se e al sec o s such as he au omo i e and
ae ospace indus ies. I could also ind i s applica ion in heal hca e and
ashion [4–6]. AM enables o manu ac u e a ious ypes o ma e ials,
such as ool s eel [7] s ainless s eel 15-5PH [8] and 316 L s eel [9–11],
Inconel 718 [12–14], Ni alloy [15], Ti alloy [16,17] o Al alloy [18,19],
whose s uc u e and mechanical p ope ies can di e depending on he
p in ing pa ame e s, s a egies, hea ea men , e c. [20,21].
Gene ally, he beha iou o mos ma e ials unde dynamic loading is
di e en han unde s a ic/quasi-s a ic loading [22,23]. Machine com-
ponen s such as gea boxes, c anksha s e c. a e subjec ed o dynamic
loading dec easing hei li e. The use o dynamic es s p o ides a ma-
e ial assessmen , which helps o design new componen s. Dynamic es s
will ob ain inpu s in o he ma e ial models, which can be used o
nume ic simula ion. The simula ion p o ides eal esul s, which can be
used in he design o machine componen s. The me hods, which can be
used o e alua e dynamic p ope ies o he ma e ial a e he Spli Hop-
kinson P essu e Ba (SHPB) me hod and he Taylo An il Tes (TAT)
o en pe o med o gain ha dening beha iou s o nume ous alloys a
ul a-high s ain [24]. TAT can also be used in e e se mode o e alua e
he esponse o he ma e ial o dynamic loading o can be used in bal-
lis ics es s [25]. Using he esul s o he dynamic p ope ies in p ac ice
could lead o a be e , mo e accu a e and as e design o a machine
componen [26].
Many s udies and a icles ocused on he in es iga ion o he dy-
namic p ope ies o ma e ials. Rua e al. [27] s udied composi es wi h
epoxy esin polyme ma ix. The mic os uc u e o he es samples we e
in es iga ed using scanning elec on mic oscopy. Dynamic es s o he
ma e ial we e pe o med using he SHPB es , which p o ided s ess-
s ain cu es o di e en s ain a es. Lu and Li [28] in es iga ed he
dynamic beha iou o polyme s a high s ain a es using he SHPB. The
expe imen ally measu ed dependence o s ess on s ain o di e en
s ain a es is subsequen ly implemen ed in o he dynamic cons i u i e
Johnson-Cook equa ion including he e ec o s ain a e and empe -
a u e. Gilbe son [29] in es iga ed he dynamic p ope ies o wood
using he SHPB. The de o ma ion o he sample was measu ed by s ain
* Co esponding au ho .
E-mail add ess: [email p o ec ed] (M. Jopek).
Con en s lis s a ailable a ScienceDi ec
Jou nal o Manu ac u ing P ocesses
jou nal homepage: www.else ie .com/loca e/manp o
h ps://doi.o g/10.1016/j.jmap o.2024.07.057
Recei ed 21 Ma ch 2023; Recei ed in e ised o m 15 Ap il 2024; Accep ed 10 July 2024
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
284
gauge and digi al image analysis. SHPB has been ound o be a use ul
ool o assessing he ma e ial p ope ies o wood subjec ed o high
s ain a es o sho loading imes. Chen e al. [30] in es iga ed he
dynamic p ope ies o specimens made om conc e e. Tes ing was
pe o med using The SHPB o di e en loading angles and di e en
impac eloci ies. Fo lowe impac eloci ies, he s ess-s ain cu e
ea u ed a simila cou se o quasi-s a ic loading, in which he ini ial
c ack occu s in he cen e o he specimen and p opaga es ou wa d.
Impac eloci y has a signi ican ole in e ms o local s ess dis ibu ion
in he sample. Kang e al. [31] compa ed he dynamic p ope ies o shale
and g ani e. Dynamic p ope ies we e e alua ed using SHPB. They
ound ha dynamic loading educed he impac s eng h. Renliang e al.
[32] in es iga ed he dynamic beha iou o sands one ia he SHPB. The
empe a u e o he samples was main ained a −15 ◦C du ing he
expe imen . The es esul s e ealed ha when he a e age s ain a e
was low, he sample s eng h changed g adually bu when i was high,
i s s eng h changed apidly. Li, Xu, Chen e al. [33] in es iga ed he
dynamic p ope ies o coal samples subjec ed o di e en impac e-
loci ies. They obse ed an ob ious s ain a e e ec on he dynamic
s eng h o specimens, which exhibi ed c acks unde de ined impac ed
angle, a ec ing s ess concen a ion in specimens and changed hei
dynamic beha iou .
High demands on he high-se ies p oduc ion o such componen s,
which a e ypically manu ac u ed om Fe ma e ial by au oma ic
sequen ial machines, which can p oduce componen s a s ain a es up
o 10
3
s
−1
. To ensu e success ul indus ial p oduc ion he mapping o
dynamic beha iou o he used ma e ial is c i ical. Liu e al. [34] used
SHPB o he in es iga ion o U71Mn s eel (used o ails) he dynamic
p ope ies o e a wide ange o s ain a es and empe a u es. Johnson-
Cook models we e de e mined ega ding his ma e ial based on he
expe imen al da a. Jopek [35] in es iga ed he dynamic beha iou o
TRISTAL low ca bon s eel using he TAT. The expe imen was pe o med
on a de ice in he labo a o y o high de o ma ion a es a he Facul y o
Mechanical Enginee ing in B no. The LS DYNA p og am was used o
simula e he mechanical beha iou o TRISTAL s eel unde dynamic
loading. Kuncicka e al. [36] showed he esul s o he impo an pa-
ame e s implemen ed in Johnson-Cook cons i u i e equa ion o TRIS-
TAL s eel. Nume ic simula ion con i med a sa is ac o y co ela ion wi h
expe imen ally obse ed da a.
The s udy o dynamic beha iou o ma e ials p oduced by he 3D
p in ing me hod ha e been add essed by se e al s udies. Zhang e al.
[37] in es iga ed he dynamic p ope ies o 3D-p in ed ce amics. Due o
di e en s uc u es o AM pa compa ed o adi ionally manu ac u ed
he di e ences in dynamic beha iou was obse ed. Sha ma e al. [38]
in es iga ed he e ec o p in ing pa ame e s on he dynamic beha iou
o polyamide samples p oduced by he selec i e lase mel ing (SLM)
me hod. S o age modulus inc eases as he lase powe , bed empe a u e
and scan leng h inc eased while i dec eased wi h he inc ease in he
scan spacing. Mansou e al. [39] in es iga ed he dynamic p ope ies o
PLA ma e ial samples p oduced ia FDM echnology. A ew samples
we e ein o ced wi h g aphene and subsequen ly subjec ed o dynamic
es s. The esul s showed ha he inco po a ion o g aphene imp o ed
he elas ic modulus, s eng h, and ha dness o he 3D p in ed samples.
S udies [40,41] in es iga ed he dynamic beha iou o Ti-6Al-4 V
samples ab ica ed by AM. The esul s ob ained h ough nume ic
simula ion showed a linea ela ionship wi h expe imen ally ob ained
esul s. Dynamic-mechanical p ope ies o AM AlSi10Mg aluminium
alloy we e in es iga ed ia SHPB o gain s ess-s ain cu es. Di e ences
in he dynamic p ope ies o his alloy p oduced wi h di e en ma e ial
o ien a ions accompanied wi h aniso opic p ope ies we e obse ed
[42–44]. A se ies o TATs we e pe o med on addi i ely (by SLM) and
con en ionally manu ac u ed 316 L s ainless s eel samples. A di e ence
in dynamic p ope ies was obse ed be ween e ical, ho izon al (SLM)
and con en ionally manu ac u ed specimens [45,46]. Resea che s
[47,48] es ed AM as-buil ma aging s eel specimens, which we e sub-
jec ed o dynamic loadings o in es iga e he dynamic beha iou ,
de o ma ion mechanisms, mic os uc u al and ex u e e olu ion ia
SHPB. Resul s showed, as-buil samples exhibi ed ac u e a he s ain
a e o 3500 s
−1
.
Ma aging s eel p oduced by AM is no pe ec ly known in ega d o
he dynamic beha iou . No many exis ing s udies we e ocused on
dynamic in es iga ion o M300 ma aging s eel ab ica ed ia SLM. The
aim o his s udy is o analyse he dynamic beha iou o M300 ma aging
s eel ia Taylo an il es . Mechanical p ope ies especially comp essi e
yield s eng h and mic oha dness in as-p in ed s a e we e e alua ed o
gain he in o ma ion abou he ma e ial model, which is implemen ed
in o he Johnson-Cook cons i u i e equa ion and subsequen ly used o
nume ic simula ion. The Real expe imen is accompanied wi h he
ollowing analysis e ealing a se e e s uc u e change. C ys allog aphic
ex u e, a e age g ain size, high angle g ain bounda ies and geome i-
cally necessa y disloca ion densi y a e desc ibed in de ail.
2. Expe imen al p ocedu e
Me al powde o he M300 ma aging s eel was used o p oduce he
samples. Fou a ious ypes o samples, which we e used o di e en
ypes o analysis we e ab ica ed ( ypes o samples a e lis ed in Table 1).
Fu he mo e, he chemical composi ion o as-p in ed sample ( ype 1)
was de e mined using he Q4 TASMAN (B uke , Rudice, Czech Repub-
lic) de ice. The gained chemical composi ion o his sample (p esen ed
in Table 2) complied wi h he i gin chemical composi ion o powde
p o ided by he p oduce . Cylind ical samples o es ing we e ab i-
ca ed using he RENISHAW RenAM 500E (RENISHAW, New Mills, UK)
3D p in e . Meande Ha ching Pa en s a egy wi h 67◦ o a ion a e
each laye was used o ab ica ion o he samples (see Fig. 1a). The
s a egy p o ides su icien mel ing p ocess, which exhibi s low po osi y
and o ma ion o a a ou able s uc u e [49]. Sample po osi y ( ype 2)
was e alua ed by op ical mic oscope Olympus DSX500, which was used
o scan he su ace o he sample. The building di ec ion (BD) was
di ec ed o he Z axis ( e ical di ec ion). P ocess pa ame e s used o
ab ica ion a e lis ed in Table 3. The eq. (1) [50,51] was used o he
calcula ion o he ene gy densi y, which was se du ing he building
p ocess.
E=P
h (1)
whe e E is lase ene gy densi y (J.mm
−3
), P is lase powe (W), is
scanning speed (mm.s
−1
), h is ha ch spacing (mm) and is laye hick-
ness (mm).
Mic oha dness o he samples ( ype 3) was measu ed in as-p in ed
s a e. Mic oha dness measu emen was pe o med in wo a ious di-
ec ions i.e. ho izon al and e ical, using load o 200 g and dwell ime
10s. To gain he comp essi e yield s eng h, necessa y machining
ope a ion was ca ied ou . Bo h aces o he sample we e no pe ec ly
la a e ab ica ion ( he e was a suppo on he i s ace and he second
ace was no la ). Pos p ocess ace u ning b ough a ou able su ace
quali y on bo h aces. Subsequen ly he samples we e placed in o a
special ix u e, which was used o comp essi e es and we e p essed a
he cons an speed 10 mm.min
−1
a he oom empe a u e 22 ◦C±1.
Machine wi h an EDC 60 (B no, Czech Republic) con ol uni was used
o comp essi e loading. Fo da a acquisi ion he TIRA es .2.1 so -
wa e was used. S ess–loga i hmic s ain cu es we e de e mined om
acqui ed da a.
Table 1
Types o di e en samples used o di e en ype o analysis.
Type Analysis s a e amoun [−]
1 Chemical composi ion as- ab ica ed 1
2 Po osi y e alua ion as- ab ica ed 1
3 Tes ing o mechanical p ope ies as- ab ica ed 8
4 Dynamic es ing as- ab ica ed 1
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
285
Tes o dynamic beha iou ia TAT ook place in he labo a o y o
high s ain a es a he Facul y o Mechanical Enginee ing BUT in B no.
The de ice used o es ing o he dynamic p ope ies is shown in Fig. 2a.
The sample ( ype 4) oge he wi h he ca ie (see Fig. 2b) is placed in
he ai essel om whe e he sample was i ed owa ds he ixed ba .
Imminen ly he sample was sepa a ed om he ca ie , he impac e-
loci y was measu ed. The impac eloci y eached max. Value o 185 m.
s
−1
in his expe imen . Fig. 2c shows ini ial dimensions o he sample
used o dynamic es ing, whe e L
0
is he leng h o he sample and D
1
and
D
2
a e diame e s on bo h sample aces. Fig. 2d ep esen s ma e ial model
wi h he key pa ame e s (L
= inal leng h, X =leng h o non-de o med
a ea, L =leng h o de o med a ea, D1 =diame e o non-de o med
cylind ical a ea, D
max
=max. Diame e a e de o ma ion) subse-
quen ly in eg a ed in he nume ic simula ion.
De ailed s uc u e obse a ion o sample a e TAT, which was p e-
pa ed by puck cas ing and au oma ically polished and e ched by 2 %
ni al solu ion was examined. Mic oha dness o de o med sample was
measu ed in YZ plane (see Fig. 1b) along and pe pendicula o sample
axis (see Fig. 1c). The s uc u e was obse ed in he YZ plane using he
Olympus DSX500 (Olympus, P ag, Czech Republic) ligh mic oscope
and he KEYENCE VHX-F (KEYENCE, Mechelen, Belgium) digi al mi-
c oscope. Tescan Ly a 3 XMU FEG/SEMxFIB (Tescan, B no, Czech Re-
public) wi h Symme y EBSD de ec o was used o de ailed s udy o he
mic os uc u e. The scan s ep o he EBSD (elec on-backsca e )
scanning was 0.15
μ
m.
Nume ical simula ion o TAT was ealised using so wa e ANSYS
Explici dynamic (Ansys Inc., Canonsbu g, Pennsyl ania, USA). Hexag-
onal mesh was applied o e alua e he sample a e TAT ia ini e
elemen me hod (FEM). Close o 270 housand elemen s wi h 308
housand nodes we e implemen ed o he de ail de ini ion, wi h no
applied e-meshing. The s a ing empe a u e was se as 22 ◦C. The TAT
nume ical simula ion was ca ied ou using Johnson-Cook (J–C) eq. (2).
Each pa ame e om he equa ion was de e mined expe imen ally and
compa ed o pa ame e s acqui ed by he nume ic simula ion.
σ
= (
σ
0+Bφn) • ⎛
⎝1+Cln
˙
φ
˙
φ0
⎞
⎠• (1−T*m)(2)
whe e
σ
0
is s a ic low s ess, B is wo k ha dening coe icien , ˙
φis s ain
a e, n is wo k ha dening exponen , C is s ain a e sensi i i y, m is he
he mal so ening coe icien , and T* is homological empe a u e
de ined in he ange 0 <T* <1 by eq. (3)
T*=T−T0
Tm−T0
(3)
whe e T
0
is he e e ence empe a u e (a s a ic low s ess
σ
0
=
σ
), and
T
m
is he mel ing empe a u e.
3. Resul s and discussions
The p ocess o 3D p in ing is based on he concep o placing each
laye by laye un il he whole pa is ab ica ed. Di ec p in ed su ace is
depic ed in Fig. 3.Fig. 3a shows he on iew o he as-p in ed sample
whe e he ha ching pa hs a e clea ly isible. Dis ance be ween each pa h
is app oxima ely equal o 0.095 mm (ha ch spacing). Fig. 3b shows he
side iew o he p in ed sample. This su ace ea u ed a non-su icien
su ace quali y a e p in ing. The co e laye o p in ed samples con-
ains plen y o mic opo es and oids, which can nega i ely a ec dy-
namic and mechanical p ope ies [52]. The e o e, i is needed o
machine su aces, which a e conside ed o be unc ional.
AM echnology especially SLM can p oduce nea ly ully dense and
high-pe o mance pa s o a e y complex shape [53]. The combina ion
o implemen ed p ocess pa ame e s could a ec he o ming s uc u e
and he po osi y [54]. Po es, ca i ies, o oids could appea due o he
p o ec ing gas, which is en apped du ing he sin e ing p ocess [55,56].
S uc u e, which epo s lowe po osi y would ea u e highe a igue
esis ance and mechanical p ope ies [57]. Po osi y was examined on
Table 2
Chemical composi ion o es ed sample.
Elemen Ni Co Mo Ti Si Mn C P Fe
Q4 TASMAN [W %] 18.38 8.84 4.67 0.71 0.01 0.04 0.02 0.02 66.40
Fig. 1. (a) Meande Ha ching Pa en 67
◦ o a ion a e each laye and (b) C oss-
sec ion plane depic ed in he sample subjec ed o TAT and (c) lines 1–3 used o
mic oha dness measu emen and places I-III in YZ plane used o s uc u e
obse a ion.
Table 3
P ocess pa ame e s used o ab ica ion o he samples.
Ene gy
densi y [J/
mm
3
]
Lase
powe [W]
Scanning speed
[mm/s]
Lase
hickness
[mm]
Ha ch
spacing
[mm]
133 410 810 0.04 0.095
Fig. 2. (a) De ice used o es ing o dynamic p ope ies ia TAT, (b) assemble
con ains o sample and ca ie and ma e ial model (c) be o e de o ma ion (d)
a e de o ma ion.
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
286
he sample ( ype 2 men ioned in Table 1), which was ab ica ed wi h
iden ical p ocess pa ame e s. Po osi y was e alua ed in ho izon al (see
Fig. 4a) and e ical di ec ion (see Fig. 4b). Th ee indi idual planes in
each di ec ion (pe pendicula and pa allel o BD) we e chosen. The
planes we e si ua ed on op, in middle heigh and in he bo om o he
sample. These planes we e sepa a ely scanned on op ical mic oscope
Olympus DSX500. Po osi y o he sample is calcula ed as a e age alue
om each single e alua ed plane (see Table 4). Fig. 4 shows he mic o
and mac o po es, which a e si ua ed dominan ly in co e laye o he
sample. In case o emo al he co e laye (0.4 mm om su ace) he
global po osi y would dec ease d ama ically. The po osi y was also
e alua ed wi hou conside ing he co e laye , which b ough he sig-
ni ican educ ion o po osi y.
3.1. Mechanical p ope ies
The as-p in ed samples ( ype 3 co esponding o Table 1) we e used
o he mic oha dness e alua ion. Fou indi idual samples we e
measu ed o de e mine mic oha dness in ho izon al (pe pendicula o
BD) and e ical (pa allel o BD) di ec ions, which is depic ed in Fig. 5.
The middle heigh plane was used o measu e mic oha dness in
ho izon al di ec ion due o he expec a ions o he highes po osi y
connec ed wi h lowe mic oha dness [58]. The esul ing alues o
mic oha dness a e gi en as he a e age alues calcula ed om 12 in-
den a ions in each di ec ion. A e age mic oha dness in ho izon al and
e ical di ec ion ea u ed o 411 HV and 410 HV espec i ely. I could
be concluded; he mic oha dness is independen on i s measu ing
di ec ion.
Bo h aces o as-p in ed samples ( ype 3) we e no pe ec ly la a e
ab ica ion. The i s ace o he sample ea u ed a building suppo , and
he second ace did no exhibi wi h an app op ia e su ace quali y. Face
u ning p o ided a a ou able su ace quali y, which ensu ed he su i-
cien condi ions o comp essi e es ing. The comp essi e s ess –log-
a i hmic s ain cu es o he examined samples a e shown in Fig. 6. The
di e en comp ession s oke was applied, which a ied o each sample:
sample 1 ea u ed he 6 mm s oke, sample 2 was exposed o 7 mm
comp ession s oke, sample 3 and sample 4 we e exposed o 8 mm and 9
mm comp ession s oke. Due o he a ious comp ession s oke he
imposed loga i hmic s ain was di e en o each sample. The a e age
Fig. 3. Su ace quali y in as-p in ed s a e: (a) on iew on SLM piece and (b) side iew.
Fig. 4. Ligh op ical mic oscopy (LOM) images show po osi y (c oss-sec ion in
middle heigh ) in (a, b) ho izon al di ec ion and (c, d) e ical di ec ion, (a–d)
co esponds o sample ype 2 acco ding o Table 1.
Table 4
E alua ed po osi y o he sample in ho izon al a e ical di ec ion.
SAMPLE Type 2 Po osi y in ho izon al
di ec ion [%]
Po osi y in e ical di ec ion
[%]
Sec ion 1 2 3 1 2 3
Unbounded a ea 0.161 0.180 0.170 0.160 0.150 0.190
Bounded a ea 0.022 0.025 0.031 0.025 0.023 0.029
Fig. 5. Mic oha dness o ou di e en samples in as-p in ed s a e. Mic o-
ha dness is gi en in ho izon al and e ical di ec ion.
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
287
comp essi e yield s eng h calcula ed om all samples ea u ed 1177 ±
5 MPa. Addi i e manu ac u ed pa should wi hs and he highe
dynamical load he highe mechanical p ope ies, he pa exhibi ed
[59]. The inal dimensions ( inal heigh , maximal and minimal diam-
e e ) o comp essed samples we e impu ed in o nume ic simula ion o
pe o m dynamic beha iou .
3.2. Dynamic es ing
Dynamic beha iou o he sample ( ype 4) was examined using he
TAT de ice. Dimensions o es ed sample in unde o med s a e we e
measu ed and subsequen ly used o inal e alua ion as well as he di-
mensions a e de o ma ion. U ilisa ion o acqui ed pa ame e s led o
e alua ion o dynamic beha iou ia FEM. Impac eloci y was 185 m.
s
−1
, which in lic ed uni o m plas ic de o ma ion depic ed in Fig. 7.
De o med sample can be di ided in wo cha ac e is ic a eas i.e., unnel-
like, and cylind ical a ea. The i s a ea was exposed o high s ain a e,
which led in c ea ion o he unnel-like a ea, co esponding o se e e
plas ic de o ma ion. The c ea ion o unnel-like a ea ins ead o ba el (in
case o comp essi e es ) p o ed ha he sample was exposed o high
s ain a e (dynamic loading) and was no in luenced by he ic ion. The
second a ea was de ined as unde o med cylinde wi h he ini ial diam-
e e . The ac , ha any mac o c acks we e obse ed, can be a ibu ed o
low impac eloci y. Highe impac eloci y can cause des uc ion o he
sample due o c acks ini ia ion [29]. The nex ac o , which can a ec
de o ma ion could be impu i y, oids, po es e c., con ained in co e
laye , which can lead o c ack ini ia ion and apid des uc ion o he
sample [60].
The sample a e high s ain a e was obse ed ia scanning elec on
mic oscopy (SEM). SEM was used o de ail scan o a eas con aining
de ec s on he impac ed egion o he sample, which is depic ed in Fig. 8.
The uni o m plas ic de o ma ion o he sample o ehead (depic ed in
Fig. 8a) con ained a huge numbe o aces equally sp ead in whole a ea.
Fig. 8b showing he de ail a ea con aining isible impu i ies ma ked in
yellow ci cle wi hin his a ea. In addi ion, hey can se e as a s ess
concen a o , om which c acks can ini ia e du ing he mechanical as
well as dynamic loading. The de o med su ace con ained plen y o
c acks o med a e he on al impac . Close de ail o c ack is p esen ed
in Fig. 8c. Each c ack is o med in main di ec ion wi h se e al seconda y
mic o sc a ches pe pendicula o main c ack.
3.3. Nume ical simula ion
The choice o he cons i u i e equa ion was based on se e al e-
qui emen s in ol ing he physical na u e o he e en . The J–C equa ion
includes i e pa ame e s, whe e wo pa ame e s, i.e. he s a ic low
s ess and he ha dening coe icien , we e ob ained om comp essi e
es . The acqui ed esul s om comp essi e es showed ha he
comp essi e yield s eng h a e in he ange 1150 MPa o 1204 MPa. The
alue 1204 MPa was se in J–C cons i u i e equa ion, which was used o
he TAT nume ic simula ion.
Fig. 9a shows he dependences be ween he e o s (pe cen age di -
e ences be ween he expe imen and he simula ion in he obse ed
a eas) on he s ain a e sensi i i y. These cu es we e e alua ed om
he sample, which ea u ed he 185 m.s
−1
impac speed. The pe cen age
di e ences we e obse ed in he a eas o maximum sample diame e
D
max
and inal leng h L
. The a e age e o eached a minimum alue a
C=0.138. When he s ain a e coe icien inc ease/dec ease he de-
ia ion would inc ease. A e he op imiza ion o he s ain a e sensi-
i i y pa ame e C, he so ening exponen m was also op imized. TAT
expe imen s we e also pe o med a ele a ed empe a u es, speci ically
o a measu ed su ace impac empe a u e o 175 ◦C, whe e he hea ed
sample was accele a ed owa ds he ba 's ace. A he ba 's ace, he
su ace empe a u e o he sample was eco ded wi h a non-con ac
empe a u e me e . By compa ing he con ou o he sample, namely
he maximum sample diame e D
max
and he inal leng h L
o he sample
a e he expe imen and op imizing D
max
and L
o he sample in he
nume ical simula ion gi en he eco ded su ace impac empe a u e,
he so ening exponen m was op imized. The esul s o he so ening
exponen op imiza ion can be seen in Fig. 9b.
The dependence o de o ma ion s ain on he loga i hmic de o ma-
ion was ob ained (see Fig. 10) by subs i u ing indi idual pa ame e s
in o he cons i u i e equa ion acco ding o J–C. The cu es we e plo ed
o di e en s ain a es, i.e., 0.02, 1200, 3000 s
−1
. The cu e acqui ed
by comp essi e es ( ep esen ed by he yellow line) was also included.
The obse ed de ia ion be ween yellow and blue lines (comp essi e es
and J–C equa ion) ea u ed he minimal de ia ion. The pa ame e s
Fig. 6. Comp essi e s ess –loga i hmic s ain cu es o all he examined
samples in as-buil condi ions, he sample placed in ix u e and is also included.
Fig. 7. Sample subjec ed o TAT: (a) on iew o he impac ed o ehead o he sample, (b) side iew p esen ing unnel-like and cylind ical a ea o he sample.
S. Kolomy e al.

Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
288
co esponding o J–C equa ion, which we e inally ob ained by nume ic
simula ion a e shown in Table 5. The esul s o he e ec i e s ain, he
ac ual s ain in indi idual axis is depic ed in Fig. 11a-d. Fig. 11a shows
he dis ibu ion o XY s ain componen s h oughou he es ed sample
a e TAT, which exhibi ed he highes de o ma ion a impac ed o e-
head. Nume ically p edic ed dis ibu ions o he s ess is depic ed in
Fig. 8. SEM images o he de o med TAT sample o ehead imposed o high s ain a e: (a) on iew o he sample, (b) a ea o in e es , (c) de ail o mic o c ack.
Fig. 9. Dependence o he de ia ion on he s ain a e sensi i i y (a) and dependence o he de ia ion on he so ening exponen m (b).
Fig. 10. Dependence o de o ma ion s ain on he loga i hmic de o ma ion.
Table 5
Nume ically ob ained pa ame e s o J–C cons i u i e equa ion.
σ
0
[MPa] B [−] n [−] C [−] m [−]
1104 1099 0.449 0.138 0.46
Fig. 11. Nume ically p edic ed dis ibu ions o s ain in XY (a), dis ibu ion o
s ess (b), YY s ain (c) and XX s ain (d).
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
289
Fig. 11b whe eas Fig. 11c p edic s he dis ibu ion o YY s ain wi hin
es ed sample, which eached maximum in icini y o he cen e.
Fig. 11d p edic s dis ibu ion o XX s ain in he TAT es ed sample.
3.4. Mic oha dness e alua ion
Mic oha dness in de o med s a e a e TAT was e alua ed in e ical
(YZ plane is depic ed Fig. 1b) di ec ion. The mic oha dness (acco ding
o Vicke s HV 0.2) was e alua ed in h ee indi idual measu emen s
(lines 1–3 co esponding o Fig. 1c) in longi udinal and ans e se di-
ec ion. Mic oha dness in line 1 (depic ed in Fig. 12a) was measu ed
along he sample axis. A o al o 193 indi idual inden ions in 0.1 mm
we e pe o med in his line. The cou se o he mic oha dness co e-
sponds wi h he con ou (depic ed in Fig. 12a) o de o med sample. The
mic oha dness copies he cou se o he con ou , which eached he
highes obse ed alue (465 HV) in he icini y o he impac ed sample
o ehead due o se e e plas ic de o ma ion no iced in his egion. This is
an inc ease o 13,1 % wi hin his a ea, compa ed o he sample in as-
p in ed s a e. The cou se shows ha he mic oha dness dec eased wi h
he inc easing dis ance, which is p obably caused due o ac o s co e-
sponding wi h a e age g ain size, high angle g ain bounda ies and
disloca ion densi y. These ac o s we e a ec ed by se e e plas ic
de o ma ion (desc ibed in Sec ion 3.5). The e alua ed mic oha dness
oscilla ed wi hin cylind ical a ea (inc eased and dec eased) acco ding o
he place, whe e he mic oha dness was measu ed. The s uc u e (close
iew is desc ibed in ollowing chap e ) o he as-buil samples ea u ed
mel ing pool s uc u e wi h wo dis inc egions, which co esponds o
di e en e ching con as (see Fig. 12A2). Da ke a eas p esen ing a
empe ed ma ensi e egion, which al e na e wi h b igh e a eas co e-
sponding o less ex ensi e empe ing [61]. SEM image (see Fig. 12A1)
e ealed a p esence o ine seconda y ca bides wi hin empe ed a ea.
The mic oha dness measu emen s con i med he lowe mic oha dness
o he da ke a eas (T =Tempe ed =393 ±5 HV 0.2), hen b igh e
a eas o less empe ed ma ensi e (Q =Quench =420 ±5 HV 0.2),
which can be conside ed as quickly quenched egion. O he cu en
wo k [62] discussed he ac ha as each subsequen laye is deposi ed,
he empe a u e inc eases due o hea ans e om he solidi ying laye
owa ds o he p e iously deposi ed laye . The inc ease o empe a u e
may cause he empe ing p ocess in neighbou ing laye s (i.e., in insic
empe ing du ing he SLM p ocess). Based on acqui ed da a, he cylin-
d ical a ea o as-de o med sample can be conside ed o ha e he same
mic oha dness as he sample in as-p in ed s a e. In o he wo ds, he
s ain a e in luenced he mic oha dness only in impac ed unnel-like
a ea o he sample, as well as he cylind ical a ea wi hin he sample
exhibi ed no signi ican changes.
Mic oha dness in line 2 and 3 (see Fig. 12b) was measu ed pe pen-
dicula o he sample axis. To al o 33 and 26 indi idual inden ions in
dis ance o 0.2 mm we e pe o med in hese lines, whe e line 2 p esen s
highe a e age alue (459 ±8 HV) o mic oha dness han line 3 (409 ±
7 HV). This is an inc ease o 12.2 % co esponding wi h geome ical and
s uc u e changes a ec ed by se e e plas ic de o ma ion, lowe a e age
g ain size and high ac ion o high-angle g ain bounda ies (HAGB,
desc ibed in ollowing chap e in de ail). Conside ing he cou se o he
alues in each line, acqui ed da a esul ed highe dispe sion in line 3
co esponding o di e en measu ed egion ( empe ed and quench). The
dispe sion in line 2 was diminished due he o e whelming e ec o
lowe a e age g ain size, high ac ion HAGB and disloca ion densi y.
3.5. S uc u e obse a ion
Fig. 13 shows a ligh op ical mic oscopy image aken om he
sample subjec ed o dynamic es ing ia TAT. The images ep esen he
longi udinal c oss-sec ion in YZ plane. The s uc u e in he cylind ical
a ea o he sample shows (see Fig. 13a) isible scanning pa hs and
cha ac e is ic mel pool s uc u e ypically c ea ed by he sin e ing
p ocess. The s uc u e ea u es semi-ellip ical g ains c ys allizing in he
solidi ying laye , which ha e hei longe axis pe pendicula o he lase
beam. The deposi ed laye is co e ed wi h he ollowing scanning pa h
c ea ing he o e lapped a eas. This ype o obse ed s uc u e is ypical
o c oss-sec ion made pa allel o he building di ec ion. SLM p ocess
causes a nonuni o mal cooling a e, which is slowe inside he mel pool
han a he bounda y esul ing in a di e en c ys alliza ion a es and
undesi able seg ega ion inside he mel ing pools [63]. This seg ega ion
can a ec mechanical p ope ies o pieces p oduced ia SLM. Due o
lowe se laye hickness (40
μ
m), i can be p edic ed ha indi idual
laye s could be emel ed se e al imes. The emel ing p ocess can cause
pa ial annealing o he al eady deposi ed laye esul ing in nonhomo-
geneous mechanical p ope ies. S uc u e in unnel-like a ea o he
sample is depic ed in Fig. 13b. De o ma ion unde s ain a e en ailed in
a change o s uc u e. The shape o a mel pools exhibi ed longe main
axis and sho e seconda y axis compa ed o pools in cylind ical a ea
esul ing in change o mechanical p ope ies.
EBSD O ien a ion image maps (OIMs) (depic ed in Fig. 14) we e
cons uc ed on images cap u ed a 1000×magni ica ion ep esen lon-
gi udinal (YZ plane) c oss-sec ion o he sample subjec ed o dynamic
es ia TAT. The g ains a e shown in he maps, using colou s ( ed, g een
and blue) ela ing o hei indi idual o ien a ions along he h ee p in-
cipal c ys al di ec ions i.e., 〈001〉,〈101〉, and 〈111〉, acco ding o Mille
indices ( he legend iangle is depic ed in each igu e). These o ien a ion
maps a e p esen ed on each a ea I-III co esponding o Fig. 1c. The g ain
o ien a ions in each a ea we e obse ed pa allel o he building di ec-
ion i.e., he longi udinal images (YZ plane) we e e alua ed pa allel o
he x axis (|| x).
G ain s uc u e in he cylind ical a ea (depic ed in Fig. 14a) ea u ed
mos ly an i egula shape wi hin his a ea I and exhibi ed no endency o
o m in ce ain o ien a ion. G ain s uc u e depic ed in Fig. 14d and g
p esen clus e s o ine equiaxed g ain and ew elonga ed g ains, which
can be seen legibly. Conside ing he OIM and o ien a ion oge he , i
appea s ha he elonga ed g ains o m pe pendicula o he sample axis.
Fig. 12. Dependence o Vicke s mic oha dness on dis ance in YZ plane: (a)
measu ed mic oha dness in line 1, (A1) p esence o ine seconda y ca bides,
(A2) wo di e en egions i.e., empe ed, and quenched s uc u e, (b) measu ed
mic oha dness in line 2 a 3.
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
290
Fig. 14d desc ibes elonga ed g ains in he cen e o he sample, which
ea u e a endency o o m he <101>||z p e e en ial o ien a ion as well
as he a ea a he bounda y o he sample (see Fig. 14g) exhibi s he same
endency. Such clus e s o ine equiaxed g ains appea in icini y o he
impac ed o ehead, whe e he applied s ess eached he maximum
alue. The lowe impac ed s ess (co ela e wi h nume ic simula ion) on
he edge o de o med egion o he sample esul ed in a lowe numbe o
such clus e s o ine g ains. P asad e al. [64] obse ed c ea ion o he
clus e o ine g ains in a eas which we e subjec ed o he emel ing
p ocess o successi e laye s.
The a e age g ain size in all a eas was examined (examina ion was
ca ied ou in YZ plane conside ing he a eas I-III, see OIMs images
depic ed in Fig. 14a, d, g) using g ain e e diame e (de ined as a
maximum dis ance be ween wo poin s wi hin a single g ain). In each
a ea I-III he a e age g ain size sligh ly a ied, bu he highes obse ed
di e ence was among a eas I and II co esponding o cylind ical and
unnel-like egion, espec i ely. A e age max. G ain e e diame e in
a ea I (cylind ical shape o he sample, which was no signi ican ly
a ec ed wi h s ain a e) was e alua ed as 10.2
μ
m ( he examined g ain
size in a ea I is depic ed in Fig. 14b). A ea II and III exhibi ed a s uc u e
change compa ed o a ea I. Due o s ain a e a signi ican g ain
e inemen was obse ed wi hin a eas II and III (each a ea II and III was
chosen in unnel-like a ea o he sample). The a e age g ain size
dec eased o 3.1
μ
m and 3.6
μ
m (see Fig. 14e and h) in a ea II and III
espec i ely. This is an almos h ee imes ine s uc u e compa ed o
a ea I ( he cylind ical pa o he sample).
The c ys allog aphic ex u e in a eas I, II, and III was s udied
conside ing he in e se pole igu es (IPFs) o YZ plane. IPFs cap u ed in
a ea I (see Fig. 14c) ea u ed a dominan o ien a ion, which is o med o
〈111〉|| z. The c ys allog aphic ex u e o he as-buil sample can be
a ec ed by he ene gy densi y deposi ed du ing sin e ing p ocess
[65–67]. Fig. 14 and i showing cha ac e is ic IPFs o a eas II and III
si ua ed in he unnel-like a ea o impac ed o ehead. Conside ing he
IPFs o de o med egion in a ea II, i is e iden ha he p e alen c ys al
o ien a ion along he build di ec ion was o med o <001>|| x o ien-
a ion as well as in a ea III. The c ys allog aphic ex u e in hese a eas is
ela ed a he o he impac de o ma ion han o he sin e ing p ocess.
The HAGB ac ion (analysis based on OIM images, h eshold o a high-
angle g ain bounda y conside ed o be 15) in cylind ical a ea I exhibi ed
30.6 %, which was he lowes obse ed ac ion. The obse ed HAGB
exhibi ed no signi ican di e ence in a eas II and III (examined HAGB in
bo h a eas we e 50.8 % and 48.2 % espec i ely). I is e iden ha a e
se e e plas ic de o ma ion he inc ease o HAGB in unnel-like a ea o
he sample was obse ed. Howe e , he highes HAGB ac ion was
obse ed in he cen e o he impac ed o ehead.
Fig. 15 shows geome ically necessa y disloca ion (GND) densi y
maps es ima ed om he EBSD o ien a ion da a co esponding o a ea I-
III. GNDs ha e been mapped in ield 100 ×100
μ
m a ound g ain
bounda ies a ec ed by s ain a e. Black pixels in each map a e co e-
sponding o non-indexed egions. Colou -scale, which is p esen ed in
each map illus a es he es ima ed amoun o disloca ion densi y
(numbe o disloca ions/m
2
) con ained wi hin each measu ed pixel on
he map. Fig. 15a p esen s acqui ed GND in a ea I, which co esponding
o he lowes alue o 11.25 p obably due o he insu icien mac oscopic
s ess le el. The minimum GND densi y is in he cen e o he g ains wi h
high GND accumula ion in he icini y o he g ain bounda ies. G ains,
which showed a s ong endency o o m in <101>||z p e e en ial
o ien a ion exhibi ed a low GND densi y on hese slip sys ems. The GND
shows he highes le el 52.77 in he cen e o unnel-like a ea II (see
Fig. 15b) co esponding o he highes numbe o high-angle g ain
bounda ies, he lowes a e age g ain size and o he highes obse ed
mic oha dness. Fig. 15c depic s a ea III, whe e he GND dec eased as
well as a e age g ain size inc eased compa ed o a ea II. The se e e
plas ic de o ma ion ea u ed a dominan e ec in he cen e o he
unnel-like a ea o he de o med sample due o c ea ion o s uc u e wi h
he lowes a e age g ain size, highes ac ion o HAGB and GND
densi y.
Based on ob ained da a, he mic os uc u e and geome ical changes
we e in luenced by high impac eloci y accompanied wi h high s ain
a e. Mos a ec ed egion (conside ing s uc u e and geome ical shape)
was he unnel-like a ea in he icini y o impac ed o ehead o he
sample. Howe e , he cylind ical a ea I ea u ed e y simila mic o-
ha dness compa ed o as-p in ed samples. The inc ease o mic oha d-
ness in he unnel-like a ea was p obably in luenced by se e al ac o s:
a e age g ain size, numbe o disloca ions and HAGB ac ion. The
applied impac eloci y esul ed in se e e plas ic de o ma ion, which
mainly a ec ed he egion o he de o med o ehead. The a e age g ain
size dec eased due o a c ea ion o he clus e o ine g ains in he i-
cini y o he cen e sample axis. The c ea ion o such clus e s o ine
g ains was accompanied wi h o ming o disloca ions p esen ed domi-
nan ly on g ain bounda ies. The a ea II close o sample axis exhibi ed he
highes HAGB ac ion, which dec ease wi h inc easing dis ance om
he sample axis. These ac o s pe ec ly co ela e wi h nume ic simula-
ion, which con i med he highes obse ed s ess in he cen e a ea II o
he sample dec easing owa ds a ea III. Mapping o he dynamic
beha iou will ob ain a signi ican da a, which can be used in nume ic
simula ions. The acqui ed da a om comp essi e es ing we e imple-
men ed in Johnson-Cook equa ion used o nume ic simula ion. Thanks
o he J-C equa ion new dynamically loaded componen s can be
designed as e and mo e accu a e (based on nume ic simula ion).
App op ia e pa su ace quali y is expec ed o inc ease esis ance o
dynamic cyclic loading as well as he inal po osi y o he componen .
Fig. 13. Ligh op ical mic oscopy (LOM) images o a eas (a) I, (b) II p esen ed in Fig. 1c.
S. Kolomy e al.
Jou nal o Manu ac u ing P ocesses 125 (2024) 283–294
291
Fig. 14. OIMs o he sample subjec ed o dynamic es ia TAT in YZ plane (a) a ea I, (b) max. Fe e diame e in a ea I, (c) IPFs in a ea I, (d) a ea II, (e) max. Fe e
diame e in a ea II, ( ) IPFs in a ea II, (g) OIMs in a ea III, (h) max. Fe e diame e in a ea III, (i) IPFs in a ea III.
S. Kolomy e al.