Characterizing the soldering alloy type Zn-Al-Cu and study of ultrasonic soldering of Al7075/Cu combination

me als A icle Cha ac e izing he Solde ing Alloy Type Zn–Al–Cu and S udy o Ul asonic Solde ing o Al7075/Cu Combina ion Roman Kolenak 1, Igo Kos olny 1,*, Ja omi D apala 2, Paulina Babinco a 1and Ma in Sahul 1   Ci a ion: Kolenak, R.; Kos olny, I.; D apala, J.; Babinco a, P.; Sahul, M. Cha ac e izing he Solde ing Alloy Type Zn–Al–Cu and S udy o Ul asonic Solde ing o Al7075/Cu Combina ion. Me als 2021,11, 27. h ps://doi.o g/10.3390/me 11010027 Recei ed: 9 Decembe 2020 Accep ed: 22 Decembe 2020 Published: 25 Decembe 2020 Publishe ’s No e: MDPI s ays neu- al wi h ega d o ju isdic ional claims in published maps and ins i u ional a ilia ions. Copy igh : © 2020 by he au ho s. Li- censee MDPI, Basel, Swi ze land. This a icle is an open access a icle dis ibu ed unde he e ms and condi ions o he C ea i e Commons A ibu ion (CC BY) license (h ps://c ea i ecommons.o g/ licenses/by/4.0/). 1Facul y o Ma e ials Science and Technology T na a, Slo ak Uni e si y o Technology in B a isla a, Jána Bo u No. 2781/25, 917 24 T na a, Slo akia; [email p o ec ed] (R.K.); [email p o ec ed] (P.B.); [email p o ec ed] (M.S.) 2 FMT—Facul y o Ma e ials Science and Technology, Technical Uni e si y o Os a a, 17. Lis opadu 15, 708 33 Os a a, Po uba, Czech Republic; ja omi [email p o ec ed] *Co espondence: igo [email p o ec ed]; Tel.: +421-918746159 Abs ac : The aim o he esea ch was o cha ac e ize he solde ing alloy ype Zn–Al–Cu and s udy he luxless ul asonic solde ing o he combina ion o aluminum alloy ype Al7075 wi h coppe subs a e. The Zn–Al–Cu solde is o he close- o-eu ec ic ype wi h wo phase ans o ma ions: he eu ec ic ans o ma ion a 378 ◦ C and he eu ec oid ans o ma ion a 285 ◦ C . The solde mic os uc u e is o med o a ma ix composed o he solid solu ions o aluminum (Al) and zinc (Zn) in which he coppe phases CuZn 4 and CuAl 2 a e p ecipi a ed. The shea s eng h o he solde ing alloy ype Zn5Al wi h coppe addi ion eaches alues om 167 o 187 MPa and i depends on he coppe con en in he solde . The bond wi h aluminum alloy ype Al7075 is o med due o he solubili y o Al in zinc solde a he o ma ion o solid solu ion Al. Con a y o his obse a ion, he bond wi h he coppe subs a e is in his case o med due o he in e ac ion o zinc and aluminum wi h he coppe subs a e. Two new in e me allic phases, namely Al(Cu,Zn) 2 and Cu 3.2 Zn 0.7 Al 4.2 , we e o med. The a e age shea s eng h o Al7075/Zn5Al3Cu/Cu join s a ained was 134.5 MPa. Fo compa ison, he Cu/Zn5Al3Cu/Cu join a ained an a e age shea s eng h o 136.5 MPa. Keywo ds: solde ing; ul asonic; in e me allic compounds; shea s eng h 1. In oduc ion Ma e ials used in ce ain indus ial applica ions a e equi ed o be ligh , s ong, and elec ically conduc i e a he same ime. These condi ions a e me in he case o ma e ials such as coppe and aluminum. In he case o Cu/Al join s, many o he p ope ies o bo h ma e ials a e u ilized. Howe e , he ab ica ion o a sound join o hese wo ma e ials is a a he icky ma e due o physical di e ences be ween he Cu and Al elemen s. Di e en welding echnologies may be used o joining hese me als, such as ic ion, ic ion s i welding, lase o cold oll welding [ 1 – 5 ]. Howe e , solde ing is also a sui able echnology o joining hese me als. Mo eo e , solde ing can be applied also o he ab ica ion o p oduc s wi h in ica e shapes as well as o mass p oduc ion [6,7]. One possible me hod o solde ing he Cu/Al combina ion is by he applica ion o zinc solde s. This conce ns solde s alloyed wi h one o mo e elemen s. Zn-based solde s a e a sui able op ion also in iew o hei ela i ely low p ice and capabili y o eac wi h he su ace o bo h Al and Cu. The addi ion o a small amoun o sui able alloying elemen s lowe s he mel ing empe a u e o hese solde s and enhances he solde abili y. Resea ch on Zn-based solde s has been ca ied ou by many au ho s [ 8 – 14 ]. In hei wo ks, hey ha e mainly used solde s based on Zn–Al o Zn–Sn wi h he addi ion o o he elemen s. Thei esea ch was de o ed o he e ec o he alloying elemen s on he mic os uc u e, o ma ion o in e me allic phases, o he s eng h o di e en combina ions o me als o ce amics, and o he s udy o he co osion p ope ies o he solde s. Me als 2021,11, 27. h ps://doi.o g/10.3390/me 11010027 h ps://www.mdpi.com/jou nal/me als Me als 2021,11, 27 2 o 17 Feng, J. e al. [ 15 ] ocused also on he e ec o he Al con en on he p ope ies o Zn–Al solde when ab ica ing Cu/Al join s. In hei s udy, a small amoun o Ce was added o he solde and hey assessed i s e ec upon he solde abili y, he mic os uc u e o he Zn22Al solde , he mechanical p ope ies o he join , and he s uc u e o he laye o med in he bounda y o he Cu/Al join . Ma e ials such as Al alloy ype 1060 and pu e coppe we e used in hei expe imen s and au oma ic solde ing wi h an oxy-ace ylene lame was applied. The Ce con en a ied om 0.01 o 1 w . %. The Zn(4–6)Al(1–5)Cu alloy des ined o highe applica ion empe a u es was de- signed wi h a liquidus poin be ween 382 and 402 ◦ C . The inc eased Al con en imp o es he sp eadabili y and nominal elec ic esis ance bu he Cu con en does no signi ican ly a ec hese p ope ies. The added elemen s inc ease he ha dness and ensile s eng h. The s udy e ealed he a o able p ope ies o Zn–Al–Cu alloys such as good solde abili y, low nominal elec ic esis ance, and good mechanical p ope ies [ 16 ]. In [ 17 ], Zn–Al–Cu based alloys des ined o highe applica ion empe a u es we e s udied, namely he ZCA34 (Zn3Cu4Al), ZCA35 (Zn3Cu5Al), and ZCA36 (Zn3Cu6Al) alloys. The s eng h o hese alloys was measu ed by SPT (shea punch es ) in he empe a u e ange om 25 o 225 ◦ C . Loading wi h he o ce o 20 kN a he loading a e o 0.25 mm · min −1 was applied. A e loading, he shea s eng h o he s udied specimens was de e mined. In [ 18 ], he au ho s s udied he eac ions be ween he solde ypes Zn4Al and Zn4Al1Cu o highe applica ion empe a u es and coppe subs a e. The mel ing poin o hese solde s was 380 and 381 ◦ C, espec i ely. The addi ion o 1 w . % Cu esul ed in educed ac i a ion ene gy, inc eased g ow h o he IM (in e me allic) phases o Cu–Zn, and a educed e osion a e o he Cu sub- s a e. Fei Xing e al. also esea ched he solde ing o Cu using Zn-based solde s [ 19 ]. Thei esea ch included solde ing wi h Zn–Sn–Cu–Bi solde s a he empe a u e o 450 ◦ C wi h he applica ion o lux ype ZnCl 2 /NH 4 Cl a di e en eac ion imes om 10 o 90 s. They obse ed he p esence o in e me allic phases such as ε -CuZn 5 , γ -Cu 5 Zn 8 , and β -CuZn in he bounda y wi h he Cu subs a e. The shea s eng h o he o e lapped join s a ained alues om 51.6 o 76.5 MPa. The aim o ou s udy consis ed in he solde ing o Cu and Al subs a es by a luxless p ocess in ai wi h ul asound assis ance. The con ibu ion p esen s he cha ac e iza ion o Zn–Al-based solde wi h Cu addi ion. Solde s wi h 1, 2, and 3 w . % Cu we e assessed by ICP-AES (induc i ely coupled plasma-a omic emission spec ome y) and DSC (di e en ial scanning calo ime y) analyses and ensile s eng h measu emen s. The solde ed join s p ope we e ab ica ed using solde ype Zn5Al3Cu wi h 3 w . % Cu. These join s we e subjec ed o SEM/EDX analysis and a shea s eng h es . 2. Ma e ials and Me hods A e de e mina ion o he weigh p opo ions o he p epa ed expe imen al alloy, he weighing o indi idual componen s was pe o med. Ma e ials wi h a high pu i y o 4N we e used as inpu componen s o solde manu ac u e. Solde manu ac u e in he as-cas condi ion was pe o med in a acuum o en (PZP KOMPLET a.s., Dob uška, Czech Republic). The p ocedu e was as ollows: he calcula ed cha ges o solde componen s we e placed in a g aphi e boa . The boa wi h he cha ge was placed in a ube made o siliceous glass 50 mm in diame e . The ube was hen inse ed in o a ho izon al acuum esis ance o en so ha he boa was si ua ed in he hea ing zone. The ube could, i necessa y, be lushed wi h A by he lange on i s inle and he ou le on i s end. In he case o Zn-based solde s, i is mo e sui able o p epa e hem a A o e p essu e due o solde e apo a ion. The cha ge was mol en a he speci ied empe a u e. Some me als a e well soluble in he base ma ix. The dissol ing and homogeniza ion o he solde componen s las ed o app oxima ely one hou , un il he mel unde A shielding was eely cooled down. A e emo al om he o en, he o med alloy was again mel ed in a g aphi e c ucible, and a e ho ough s i ing, i was cas o a g aphi e boa whe e i was cooled down apidly. Me als 2021,11, 27 3 o 17 Th ee solde ing alloys based on Zn5Al, wi h 1, 2, and 3 w . % Cu we e p epa ed. The chemical composi ion o hese alloys is gi en in Table 1. Table 1. Composi ion o Sn–Sb–Ti alloy and he esul s o chemical analysis done by he he ICP-AES me hod [w . %]. Sample Cha ge (w . %) ICP-AES (w . %) Zn Al Cu Zn Al Cu Zn5Al1Cu 94 5 0.1 93.9 ±0.6 4.71 ±0.3 1.1 ±0.2 Zn5Al2Cu 93 5 0.2 93.1 ±0.6 4.82 ±0.4 2.01 ±0.3 Zn5Al3Cu 92 5 0.3 92.3 ±0.7 4.65 ±0.4 3.08 ±0.2 Chemical analysis o he p epa ed alloys was pe o med by he a omic emission spec ome y me hod wi h induc ion coupled plasma (ICP-AES, SPECTRO Analy ical Ins umen s GmbH, Kle e, Ge many). The analysis was ca ied ou on he ins umen ype SPECTRO VISION EOP (SPECTRO Analy ical Ins umen s GmbH, Kle e, Ge many). The samples o alloys des ined o ICP-AES analysis we e dissol ed in sui able chemical solu ions o acid and bases. The analysis p ope was pe o med on he emission a omic spec ome e (SPECTRO Analy ical Ins umen s GmbH, Kle e, Ge many) wi h a pneuma ic a omize and Sco ’s a omizing chambe . Tes pieces o he ensile s eng h es we e hen p epa ed om he solde ing alloys (Figu e 1a). The dimensions gi en in Figu e 1a a e in mm. Figu e 1. Schema ic p esen a ion o es pieces (uni : mm). (a) Tensile s eng h es piece; (b) assembly o solde ed join s. Subs a es o he ollowing ma e ials we e used o he expe imen s: • me allic Cu subs a e o 4N pu i y in he shape o discs wi h dimensions Ø 15 mm × 2 mm, •me allic Al7075 subs a e in he shape o discs wi h dimensions Ø 15 mm ×2 mm. The scheme o he solde ed join s is shown in Figu e 1b. The solde ed join s we e ab ica ed using a ho pla e wi h he mos a ic empe a u e con ol. The Si subs a e was placed on he ho pla e and hen he solde hea ed o he solde ing empe a u e was placed on i . Solde ing was pe o med using an ul asonic equipmen ype Hanuz UT2 (HANUZ s. .o. No e Mes o nad Vahom, Slo akia) wi h he pa ame e s gi en in Table 2. Solde ac i a ion was ealized ia an encapsula ed ul asonic ansduce consis ing o a piezo-elec ic oscilla ing sys em and a i anium sono ode wi h he end ip diame e o Ø 3 mm. The solde ing empe a u e was app oxima ely 20 ◦ C abo e he mel ing poin o he solde ing alloy. The solde ing empe a u e was checked by con inuous empe a u e measu emen on he ho pla e using a NiC /NiSi he mocouple. The ul asonic powe was ac i a ed o 5 s. Solde ing was ealized wi hou he use o lux. A e ul asound ac i a ion, he edundan oxide laye on he su ace o he mol en solde was emo ed. A simila p ocess was pe o med also wi h he o he subs a e. Then, bo h subs a es wi h mol en solde we e laid on each o he and hus he solde ed join was o med. The schema ic ep esen a ion o his p ocess is shown in Figu e 2and he se -up scheme o ul asonic solde ing is shown in Figu e 3. Me als 2021,11, 27 4 o 17 Table 2. Solde ing pa ame e s. Ul asound powe 400 (W) Wo king equency 40 (kHz) Ampli ude 2 (µm) Solde ing empe a u e 410 (◦C) Time o ul asound ac i a ion 5 (s) Figu e 2. Schema ic ep esen a ion o he solde ing p ocess in he p esence o ul asonic powe . Figu e 3. Se -up scheme o ul asonic solde ing. Me allog aphic p epa a ion o specimens om he solde ed join s was ealized by he s anda d me allog aphic p ocedu es used o specimen p epa a ion. G inding was pe - o med using SiC eme y pape s wi h 240, 320, and 1200 g ains/cm 2 g anula i y. Polishing was pe o med wi h diamond suspensions wi h g ain size 9, 6, and 3 µ m. Final polishing was pe o med using polishing emulsion ype OP-S (S ue s) wi h 0.2 µm g anula i y. The solde mic os uc u e was s udied using scanning elec on mic oscopy (SEM) on mic oscopes o ype TESCAN VEGA 3 (Tescan O say Holding, B no, Czech Republic) and JEOL 7600 F (JOEL L d., Tokyo, Japan) wi h an X- ay mic o-analyze ype Mic ospec Me als 2021,11, 27 5 o 17 WDX-3PC (Mic ospec L d., Pe e bo ough, NH, USA) o pe o ming he quali a i e and semi-quan i a i e chemical analysis. Fo iden i ica ion o he phase composi ion o he solde , X- ay di ac ion analysis was used, pe o med on an XRD di ac ome e ype PANaly ical X’Pe PRO (Mal e n Panaly ical L d., Mal e n, UK) wi h solde specimens o dimensions 10 mm × 10 mm × 2 mm. S ep size pa ame e was 0.013◦and scan s ep ime pa ame e was 29.07 s. Di e en ial scanning calo ime y, o also di e en ial compensa ion calo ime y, is a me hod in which he he mal p ope ies o ma e ials a e examined. The DSC analysis o he Zn–Al–Cu solde s was pe o med on equipmen ype Ne zsch STA 409 C/CD (NETZSCH-Ge ä ebau GmbH, Selb, Ge many) unde shielding wi h A gas wi h 6N pu i y. To de e mine he mechanical p ope ies o he solde ed join s, he shea s eng h es was pe o med. The measu emen was pe o med on he ollowing join : Coppe in he shape o discs wi h dimensions Ø 15 mm × 3 mm/squa e o Al7075 alloy wi h dimensions 10 mm ×10 mm ×3 mm. The schema ic ep esen a ion o he specimen is shown in Figu e 4a. The shea s eng h was measu ed on a e sa ile es ing equipmen ype LabTes 5.250SP1-VM (Labo ech L d., P aque, Czech Republic). To change he di ec ion o he axial loading o ce applied on he es specimen, a special jig was used wi h he de ined shape o he es specimen (Figu e 4b) . This shea ing jig ensu es a uni o m loading o he specimen by shea in he plane o he solde and subs a e bounda y. Figu e 4. Schema ic p esen a ion o shea s eng h measu emen . ( a ) Specimen o shea s eng h es (uni : mm); ( b ) scheme o special jig. 3. Resul s 3.1. DSC Analysis To de e mine he mel ing poin o he solde , DSC analysis was applied. The DSC cu e o solde ing alloys o ype Zn–Al–Cu ypically has wo basic peaks. The i s peak co esponds o eu ec oid ans o ma ion and he second p onounced peak co esponds o eu ec ic ans o ma ion (Figu e 5). Following he Zn–Al bina y diag am, he empe a u e o eu ec oid ans o ma ion is a ound 278 ◦ C (Figu e 6). Acco ding o [ 20 ], he ollow- ing eac ion akes place a his empe a u e: Al- ich cc (Al) + hcp (Zn) ↔ Zn- ich cc (Al). I is ob ious om he DSC cu e in Figu e 7 ha he addi ion o Cu o he solde inc eases he empe a u e o his ans o ma ion o app oxima ely 285 ◦ C . On he con a y, he empe a u e o eu ec ic ans o ma ion, which acco ding o he bina y diag am equals 381 ◦ C (Figu e 6), is sligh ly educed wi h he addi ion o Cu o he solde ing alloy. A 2 w . % Cu, he maximum empe a u e o he second peak is 379.0 ◦ C , and a 3 w . % Cu, he maximum empe a u e o ha peak is 378.4 ◦ C . Since he main base o he Zn5Al solde is close- o-eu ec ic, a he empe a u e a ound 381 ◦ C , i should be comple ely mol en. Bu he addi ion o coppe o he solde shi s he end empe a u e owa ds highe alues and ex ends he lowe sec ion o he peak (Figu e 5), whe eas in he case o Zn5Al2Cu and Zn5Al3Cu solde s, a hi d peak is c ea ed. The Zn5Al1Cu solde is o ally mol en a he empe a u e o 383.9 ◦ C , whe eas in he case o he Zn5Al3Cu solde , mel ing e mina es a 386.7 ◦ C . Table 3shows he measu ed solidus and liquidus empe a u es o hese solde s. The solde ing empe a u e is usually selec ed app oxima ely 20 ◦ C abo e he mel ing poin o he solde ing alloy, so he solde ing empe a u e applied in he expe imen s was 410 ◦ C . Me als 2021,11, 27 6 o 17 Figu e 5. DSC cu es o solde ing alloys: ( a ) Zn5Al1Cu; ( b ) Zn5Al2Cu; ( c ) Zn5Al3Cu, a he hea ing a e o 1 K · min −1 . * manually ex apola ed poin . Figu e 6. The bina y diag am o Al–Zn [20]. Me als 2021,11, 27 7 o 17 Figu e 7. The phase diag am o Al–Zn–Cu o he concen a ion o 3 w . % Cu [20]. Table 3. Solidus and liquidus empe a u es o Zn-Al-Cu solde s. Solde Solidus (◦C) Liquidus (◦C) Zn5Al1Cu 377.7 383.9 Zn5Al2Cu 371.8 386.1 Zn5Al3Cu 370.2 386.7 3.2. Mic os uc u e o Solde s Type Zn–Al–Cu The mic os uc u e was s udied by he SEM echnique in obse ing mode BSE (Back- sca e de ec o ). In he BSE mode, he measu e o da kening is indi ec ly p opo ional o he a e age a omic weigh o he elemen s p esen a he gi en poin . The ligh e elemen s a e shown as da ke — he solid solu ion Al, while he hea ie elemen s a e shown as b igh e — he solid solu ion Zn. The mic os uc u e o he Zn–Al–Cu solde is shown in Figu e 8. The s uc u e is, a i s sigh , o med o he solid solu ion Zn and he solid solu ion Al. Acco ding o he phase diag am in Figu e 8, he solde ma ix con ains also he ε -CuZn 4 phase (e en ually Cu0.2Zn0.8 phase). Fo de e mina ion o he chemical composi ion o he indi idual componen s o he solde ing alloy, local chemical EDX mic oanalysis was pe o med. The poin s o measu emen shown in Figu e 8a a e ma ked as Spec um 1 o Spec um 3. The p ima y g ains (Spec um 1) in Figu e 8a a e o med o solid solu ion Zn, whe e Cu and Al a e pa ially dissol ed. This zone is documen ed in Figu e 8d. Spec um 2 co esponds by i s composi ion o Al phase wi h a high Zn con en , which is s able abo e he empe a u e o 277 ◦ C . Figu e 8c sugges s ha e y ine lamella eu ec ics is conce ned, wi h a highe con en o Zn and lowe con en o Al han in he case o Spec um 3. The Spec a 3, 3a, and 3b ep esen he eu ec ics wi h lamella s uc u e Al + Zn + a mino i y p opo ion o ε-CuZn4 phase. Me als 2021,11, 27 8 o 17 Figu e 8. SEM/EDX analysis o ZnAl5Cu3 solde : ( a , b ) poin s o measu emen in indi idual spec a; ( c ) de ail o zone 2; (d) de ail o zone 1. The di ac ion XRD analysis o he Zn5Al3Cu solde has p o ed he p esence o solid solu ion Zn, solid solu ion Al, and in e me allic phases CuZn 4 - e and CuAl 2 - θ . The CuAl 2 phase was no iden i ied by EDX analysis. The eco d om he di ac ion analysis is documen ed in Figu e 9. Figu e 10 shows he esul s o plana EDX analysis o his solde , whe e he solde elemen s Zn, Al, and Cu a e di e en ia ed by colo . The g ains o solid solu ion Zn a e clea ly isible and also he space amongs he g ains (ligh -blue colo ) illed wi h solid solu ion Al. Coppe and i s phase CuZn4is dissipa ed mainly in he solid solu ion Zn. Me als 2021,11, 27 9 o 17 Figu e 9. Di ac ion eco d o Zn5Al3Cu solde . Figu e 10. Map o Zn, Al, and Cu elemen s in he s uc u e o Zn5Al3Cu solde . 3.3. Tensile S eng h o Solde ing Alloys Type Zn–Al–Cu The mechanical es s o Zn–Al–Cu ype solde s we e pe o med. The dimensions o he es pieces we e p oposed and calcula ed. Th ee specimens o each expe imen al solde ing alloy we e used o ensile s eng h measu emen . The loading a e o he es piece was 1 mm · min −1 . The ensile s eng h o he Zn–Al–Cu ype solde s in dependence on he coppe con en was de e mined. The esul s o he ensile es a e documen ed in he g aph in Figu e 11. Me als 2021,11, 27 16 o 17 Rega ding his iewpoin , he XDR analysis on he ac u ed su ace o he Al7075/Zn5 Al3Cu/Cu join was pe o med (Figu e 22). The p esence o Cu on he ac u ed su ace was hus p o ed. In addi ion, obse ed we e solid solu ions o aluminum and zinc and newly o med phases o coppe —CuZn 4 , CuAl 2 , Cu 3.2 Zn 0.7 Al 4.2 , we e also obse ed, which a e he esul o solde in e ac ion wi h he coppe subs a e. All hese phases we e p o ed also by EDX analysis. Figu e 22. The XRD analysis o ac u ed su ace in Al7075/Zn5Al3Cu/Cu join . 4. Conclusions The aim o he esea ch was o cha ac e ize he solde ing alloy o ype Zn–Al–Cu and o s udy whe he he selec ed composi ion o he solde ing alloy is sui able o he combina ion o coppe wi h aluminum alloy ype Al7075 wi h he applica ion o ul asonic solde ing. The ollowing esul s we e achie ed: • To de e mine he mel ing poin o he solde , DSC analysis was applied. The DSC cu e con ains wo basic peaks. The i s peak co esponds o eu ec oid ans o ma ion in he Zn–Al sys em. The second peak co esponds o eu ec ic ans o ma ion in he same sys em. I was ound ha he addi ion o Cu o he solde inc eases he empe a u e o eu ec oid ans o ma ion o app oxima ely 285 ◦ C and, ice e sa, he empe a u e o eu ec ic ans o ma ion is educed o 378 ◦C . • The mic os uc u e o solde o ype Zn–Al–Cu is o med o a eu ec ic mix u e o solid solu ions Zn + Al + Al“. Two coppe phases, CuZn 4 and CuAl 2 , we e iden i ied in he solde ma ix. • The a e age ensile s eng h o solde ing alloys o ype Zn–Al–Cu eaches alues om 167 o 187 MPa. I was ound ha he addi ion o coppe pa ially educes he ensile s eng h o solde ing alloys o ype Zn–Al–Cu. The addi ion o 3 w . % Cu o Zn5Al solde will educe he a e age ensile s eng h by 38 MPa. This is caused by he o ma ion o coppe phases o ype CuZn4and CuAl2. • The bond o aluminum alloy wi h Zn5Al3Cu solde is o med due o he dissolu ion o Al in zinc solde a he o ma ion o solid solu ion Al. The wid h o he solubili y band wi h he solid solu ion Al was 5 o 11 µm. • Two new in e me allic phases, namely Al(Cu,Zn) 2 and Cu 3.2 Zn 0.7 Al 4.2 , we e iden i ied in he bounda y o he Cu/Zn5Al3Cu join , which a e he esul o in e ac ion o he zinc solde and coppe subs a e. Beside he in e ac ion o Zn, also a signi ican e ec o Al on bond o ma ion wi h he coppe subs a e was p o ed. • The a e age shea s eng h o he Al7075/Zn5Al3Cu/Cu join had a alue o 134.5 MPa. Fo compa ison, he Cu/Zn5Al3Cu/Cu join a ained an a e age shea s eng h o 136.5 MPa. Me als 2021,11, 27 17 o 17 Au ho Con ibu ions: Concep ualiza ion, R.K. and I.K.; me hodology, R.K.; alida ion, R.K., I.K. and J.D.; o mal analysis, J.D., P.B. and M.S.; in es iga ion, R.K. and I.K.; da a cu a ion, I.K.; w i ing— o iginal d a p epa a ion, R.K.; w i ing— e iew and edi ing, I.K.; isualiza ion, I.K.; supe ision, R.K.; p ojec adminis a ion, I.K.; All au ho s ha e ead and ag eed o he published e sion o he manusc ip . Funding: This wo k was suppo ed by he Slo ak Resea ch and De elopmen Agency unde con ac no. APVV-17-0025 and by he scien i ic g an agency o he Minis y o Educa ion o he Slo ak Republic and o Slo ak Academy o Sciences unde con ac no. VEGA 1/0303/20. 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