{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T23:09:32Z","timestamp":1770419372878,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,4,17]],"date-time":"2021-04-17T00:00:00Z","timestamp":1618617600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"COMPETE2020\u2014Programa Operacional Competitividade e Internacionaliza\u00e7\u00e3o (POCI) and by national funds (PIDDAC) through FCT\/MCTES","award":["PTDC\/CTM-CTM\/31579\/2017"],"award-info":[{"award-number":["PTDC\/CTM-CTM\/31579\/2017"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metals"],"abstract":"<jats:p>This paper aims to investigate the diffusion bonding of Ti6Al4V to Al2O3. The potential of the use of reactive nanolayered thin films will also be investigated. For this purpose, Ni\/Ti multilayer thin films with a 50 nm modulation period were deposited by magnetron sputtering onto the base materials. Diffusion bonding experiments were performed at 800 \u00b0C, under 50 MPa and a dwell time of 60 min, with and without interlayers. Microstructural characterization of the interface was conducted through scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The joints experiments without interlayer were unsuccessful. The interface is characterized by the presence of a crack close to the Al2O3 base material. The results revealed that the Ni\/Ti reactive multilayers improved the diffusion bonding process, allowing for sound joints to be obtained at 800 \u00b0C for 60 min. The interface produced is characterized by a thin thickness and is mainly composed of NiTi and NiTi2 reaction layers. Mechanical characterization of the joint was assessed by hardness and reduced Young\u2019s modulus distribution maps that enhance the different phases composing the interface. The hardness maps showed that the interface exhibits a hardness distribution similar to the Al2O3, which can be advantageous to the mechanical behavior of the joints.<\/jats:p>","DOI":"10.3390\/met11040655","type":"journal-article","created":{"date-parts":[[2021,4,19]],"date-time":"2021-04-19T06:35:53Z","timestamp":1618814153000},"page":"655","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Diffusion Bonding of Ti6Al4V to Al2O3 Using Ni\/Ti Reactive Multilayers"],"prefix":"10.3390","volume":"11","author":[{"suffix":"Jr.","given":"Marcionilo","family":"Silva","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Federal University of Amazonas, General Rodrigo Octavio Jord\u00e3o Ramos ST., Manaus 69067-005, Brazil"},{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2014Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua. Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8486-5436","authenticated-orcid":false,"given":"Ana S.","family":"Ramos","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Coimbra, CEMMPRE, R. Lu\u00eds Reis Santos, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9981-3826","authenticated-orcid":false,"given":"M. Teresa","family":"Vieira","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Coimbra, CEMMPRE, R. Lu\u00eds Reis Santos, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4670-4516","authenticated-orcid":false,"given":"S\u00f3nia","family":"Sim\u00f5es","sequence":"additional","affiliation":[{"name":"Department of Metallurgical and Materials Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"LAETA\/INEGI\u2014Institute of Science and Innovation in Mechanical and Industrial Engineering, Rua. Dr. Roberto Frias, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4930","DOI":"10.3390\/ma7074930","article-title":"Welding and joining of titanium aluminides","volume":"7","author":"Cao","year":"2014","journal-title":"Materials"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1179\/1362171813Y.0000000118","article-title":"Mechanisms of joining aluminium A6061- T6 and titanium Ti\u20136Al\u20134V alloys by cold metal transfer technology","volume":"18","author":"Cao","year":"2013","journal-title":"Sci. Technol. Weld. Join."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1700764","DOI":"10.1002\/adem.201700764","article-title":"Metallurgical strategies for the joining of titanium alloys with steels","volume":"20","author":"Tomashchuk","year":"2018","journal-title":"Adv. Eng. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1002\/mawe.201400337","article-title":"Diffusion bonding of TiAl based alloy to Ti-Al-4V alloy using amorphous interlayer","volume":"46","author":"Xue","year":"2015","journal-title":"Mater. Wiss. Werkstofftech"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Sim\u00f5es, S., Ramos, A.S., Viana, F., Vieira, M.T., and Vieira, M.F. (2016). Joining of TiAl to steel by diffusion bonding with Ni\/Ti reactive multilayers. Metals, 6.","DOI":"10.3390\/met6050096"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Leyens, C., and Peters, M. (2003). Titanium and Titanium Alloys: Fundamentals and Applications, WILEY-VCH Verlag GmbH & Co. KGaA.","DOI":"10.1002\/3527602119"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1016\/j.jallcom.2016.06.212","article-title":"High temperature oxidation behavior and research status of modifications on improving high temperature oxidation resistance of titanium alloys and titanium aluminides: A review","volume":"685","author":"Dai","year":"2016","journal-title":"J. Alloys Compd."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/S0921-5093(98)01158-7","article-title":"Gamma titanium aluminide alloys\u2014An assessment within the competition of aerospace structural materials","volume":"263","author":"Dimiduk","year":"1999","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_9","unstructured":"Aldinger, F., and Weberruss, V.A. (2010). Advanced Ceramics and Future Materials: An Introduction to Structures, Properties, Technologies, Methods, WILEY-VCH Verlag GmbH & Co. KGaA."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Richerson, D.W., and Lee, W.E. (2018). Modern Ceramic Engineering: Properties, processing, and Use in Design, CRC Press, Taylor & Francis Group. [4th ed.].","DOI":"10.1201\/9780429488245"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.vacuum.2017.06.020","article-title":"Characterization of microstructure and mechanical properties of Al2O3\/TiAl joints vacuum-brazed with Ag-Cu-Ti+W composite filler","volume":"143","author":"Yang","year":"2017","journal-title":"Vacuum"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6924","DOI":"10.1016\/j.ceramint.2016.01.078","article-title":"Microstructure and mechanical properties of Al2O3 ceramic and TiAl alloy joints brazed with Ag-Cu-Ti filler metal","volume":"42","author":"Niu","year":"2016","journal-title":"Ceram. Int."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"15296","DOI":"10.1016\/j.ceramint.2017.08.069","article-title":"Brazing ZrO2 ceramic and TC4 alloy by novel WB reinforced Ag-Cu composite filler: Microstructure and properties","volume":"43","author":"Dai","year":"2017","journal-title":"Ceram. Int."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2602","DOI":"10.1007\/s11665-013-0534-y","article-title":"Effect of fabrication parameters on interface of zirconia and Ti-6Al-4V joints using Zr55Cu30Al10Ni5 amorphous filler","volume":"22","author":"Liu","year":"2013","journal-title":"J. Mater. Eng. Perform."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4385","DOI":"10.1023\/A:1020669022776","article-title":"The Al2O3-titanium adhesion in the view of the diffusion bonding process","volume":"37","author":"Travessa","year":"2002","journal-title":"J. Mater. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1023\/A:1004378520526","article-title":"Microstructure of diffusional zirconia-titanium and zirconia-(Ti-6wt% Al-4 wt% V) alloy joints","volume":"33","author":"Correia","year":"1998","journal-title":"J. Mater. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1263","DOI":"10.1016\/j.matchar.2009.05.007","article-title":"Al2O3\/Ti6Al4V diffusion bonding joints using Ag-Cu interlayer","volume":"60","author":"Barrena","year":"2009","journal-title":"Mater. Charact."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.matdes.2013.10.074","article-title":"Diffusion bonding of TiAl intermetallic and Ti3AlC2 ceramic: Interfacial microstructure and joining properties","volume":"56","author":"Cao","year":"2014","journal-title":"Mater. Des."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"592","DOI":"10.1016\/j.matdes.2014.01.029","article-title":"Evaluation on diffusion bonded joints of TiAl alloy to Ti3SiC2 ceramic with and without Ni interlayer: Interfacial microstructure and mechanical properties","volume":"57","author":"Liu","year":"2014","journal-title":"Mater. Des."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1494","DOI":"10.2320\/matertrans.M2016126","article-title":"Characterization of Al\/Ti nano multilayer as a jointing material at the interface between Cu and Al2O3","volume":"57","author":"Yi","year":"2016","journal-title":"Mater. Trans."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3528","DOI":"10.1016\/j.tsf.2012.01.001","article-title":"Characterization of Al\/Ni multilayers and their application in diffusion bonding of TiAl to TiC cermet","volume":"520","author":"Cao","year":"2012","journal-title":"Thin Solid Films"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"AlHazaa, A., Haneklaus, N., and Almutairi, Z. (2021). Impulse pressure-assisted diffusion bonding (IPADB): Review and outlook. Metals, 11.","DOI":"10.3390\/met11020323"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Cooke, K.O., and Atieh, A.M. (2020). Current trends in dissimilar diffusion bonding of titanium alloys to stainless steels, aluminium and magnesium. J. Manuf. Mater. Process., 4.","DOI":"10.3390\/jmmp4020039"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Hu, A., Janczak-Rusch, J., and Sano, T. (2019). Joining technology innovations at the macro, micro and nano levels. Appl. Sci., 9.","DOI":"10.3390\/app9173568"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1007\/s40194-017-0507-0","article-title":"TiAl diffusion bonding using Ni\/Ti multilayers","volume":"61","author":"Viana","year":"2017","journal-title":"Weld. World"},{"key":"ref_26","first-page":"7718","article-title":"Reaction zone formed during diffusion bonding of TiNi to Ti6Al4V using Ni\/Ti nanolayers","volume":"58","author":"Viana","year":"2013","journal-title":"J. Mater. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.matchemphys.2011.02.059","article-title":"Diffusion bonding of TiAl using reactive Ni\/Al nanolayers and Ti and Ni foils","volume":"128","author":"Viana","year":"2011","journal-title":"Mater. Chem. Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"972","DOI":"10.4028\/www.scientific.net\/DDF.297-301.972","article-title":"Reaction-assisted diffusion bonding of advanced materials","volume":"297\u2013301","author":"Ramos","year":"2010","journal-title":"Defect Diffus. Forum"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"353","DOI":"10.2320\/matertrans.M2017333","article-title":"Ab initio Prediction of Atomic Location of Third Elements in B2-Type TiNi","volume":"59","author":"Yamamoto","year":"2018","journal-title":"Mater. Trans."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1016\/j.apsusc.2015.07.141","article-title":"Effect of surface treatment on adhesion strength between magnetron sputtered copper thin films and alumina substrate","volume":"355","author":"Lim","year":"2015","journal-title":"Appl. Surf. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1557\/JMR.1992.1564","article-title":"Improved technique for determining hardness and elastic modulus using load and displacements sensing indentation experiments","volume":"7","author":"Oliver","year":"1992","journal-title":"J. Mater. Res."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Ishak, M. (2016). Current Issues and Problems in the Joining of Ceramic to Metal. Joining Technologies, IntechOpen.","DOI":"10.5772\/61698"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.tsf.2017.05.005","article-title":"Understanding the bonding mechanisms of directly sputtered copper thin film on an alumina substrate","volume":"634","author":"Lim","year":"2017","journal-title":"Thin Solid Films"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.intermet.2014.02.019","article-title":"In-situ thermal evolution of Ni\/Ti multilayer thin films","volume":"51","author":"Cavaleiro","year":"2014","journal-title":"Intermetallics"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1016\/j.jallcom.2015.06.037","article-title":"Phase transformations in Ni\/Ti multilayers investigated by synchrotron radiation-based X-ray diffraction","volume":"646","author":"Cavaleiro","year":"2015","journal-title":"J. Alloys Compd."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Cavaleiro, A., Ramos, A.S., Fernandes, F., Baehtz, C., and Vieira, M.T. (2018). Interaction between Ni\/Ti nanomultilayers and bulk Ti-6Al-4V during heat treatment. Metals, 8.","DOI":"10.3390\/met8110878"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1496","DOI":"10.1016\/j.jeurceramsoc.2019.11.066","article-title":"Microstructure evolution and bonding strength of the Al2O3\/Al2O3 interface brazed via Ni-Ti intermetallic phases","volume":"40","author":"Lu","year":"2020","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1007\/BF02664854","article-title":"The Al-Ti-V (aluminum-titanium-vanadium) system","volume":"16","author":"Hayes","year":"1995","journal-title":"J. Phase Equilibria"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1337","DOI":"10.1016\/S0966-9795(99)00054-0","article-title":"The ternary system Al-Ni-Ti Part I: Isothermal section at 900 \u00b0C.; Experimental investigation and thermodynamic calculation","volume":"7","author":"Humeau","year":"1999","journal-title":"Intermetallics"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1016\/j.msea.2006.08.019","article-title":"Mechanism of forming interfacial intermetallic compounds at interface for solid state diffusion bonding of dissimilar materials","volume":"437","author":"He","year":"2006","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2455","DOI":"10.1007\/BF01114292","article-title":"Solid-state bonding of alumina to austenitic stainless steel","volume":"21","author":"Hatakeyama","year":"1986","journal-title":"J. Mater. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1007\/BF02670294","article-title":"Reaction of Ti and Ti-Al alloys with alumina","volume":"22","author":"Misra","year":"1991","journal-title":"Metall. Trans. A"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1016\/j.msea.2015.04.079","article-title":"Hardening behavior and phase decomposition in very Ni-rich Nitinol alloys","volume":"639","author":"Hornbuckle","year":"2015","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"116354","DOI":"10.1016\/j.jmatprotec.2019.116354","article-title":"Follow-up structural evolution of Ni\/Ti reactive nano and microlayers during diffusion bonding of NiTi to Ti6Al4V in a synchrotron beamline","volume":"275","author":"Cavaleiro","year":"2020","journal-title":"J. Mater. Process. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.matdes.2017.05.055","article-title":"Intermetallic formation and mechanical properties of Ni-Ti diffusion couples","volume":"130","author":"Hu","year":"2017","journal-title":"Mater. Des."}],"container-title":["Metals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4701\/11\/4\/655\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:49:13Z","timestamp":1760161753000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4701\/11\/4\/655"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,17]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,4]]}},"alternative-id":["met11040655"],"URL":"https:\/\/doi.org\/10.3390\/met11040655","relation":{},"ISSN":["2075-4701"],"issn-type":[{"value":"2075-4701","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,17]]}}}