{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,17]],"date-time":"2026-01-17T07:45:55Z","timestamp":1768635955269,"version":"3.49.0"},"reference-count":28,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2016,4,25]],"date-time":"2016-04-25T00:00:00Z","timestamp":1461542400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BDP\/109788\/2015"],"award-info":[{"award-number":["SFRH\/BDP\/109788\/2015"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metals"],"abstract":"<jats:p>Dissimilar diffusion bonds of TiAl alloy to AISI 310 stainless steel using Ni\/Ti reactive multilayers were studied in this investigation. The Ni and Ti alternating layers were deposited by d.c. magnetron sputtering onto the base materials, with a bilayer thickness of 30 and 60 nm. Joining experiments were performed at 700 and 800 \u00b0C for 60 min under pressures of 50 and 10 MPa. The effectiveness of using Ni\/Ti multilayers to improve the bonding process was assessed by microstructural characterization of the interface and by mechanical tests. Diffusion bonded joints were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), high resolution TEM (HRTEM) and Fast Fourier transform (FFT). The bonding interfaces are thin (approximately 5 \u00b5m thick) with a layered microstructure. For all joints, the interface is mainly composed of equiaxed grains of NiTi and NiTi2. The thickness and number of layers depends on the joining conditions and bilayer thickness of the multilayers. Mechanical characterization of the joints was performed by nanoindentation and shear tests. Young\u00b4s modulus distribution maps highlight the phase differences across the joint\u00b4s interface. The highest shear strength value is obtained for the joint produced at 800 \u00b0C for 60 min under a pressure of 10 MPa using Ni\/Ti multilayers with 30 nm of bilayer thickness.<\/jats:p>","DOI":"10.3390\/met6050096","type":"journal-article","created":{"date-parts":[[2016,4,25]],"date-time":"2016-04-25T10:02:36Z","timestamp":1461578556000},"page":"96","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Joining of TiAl to Steel by Diffusion Bonding with Ni\/Ti Reactive Multilayers"],"prefix":"10.3390","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4670-4516","authenticated-orcid":false,"given":"S\u00f3nia","family":"Sim\u00f5es","sequence":"first","affiliation":[{"name":"CEMUC, Department of Metallurgical and Materials Engineering, University of Porto, R. Dr. Roberto Frias, Porto 4200-465, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8486-5436","authenticated-orcid":false,"given":"Ana","family":"Ramos","sequence":"additional","affiliation":[{"name":"CEMUC, Department of Mechanical Engineering, University of Coimbra, R. Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2894-771X","authenticated-orcid":false,"given":"Filomena","family":"Viana","sequence":"additional","affiliation":[{"name":"CEMUC, Department of Metallurgical and Materials Engineering, University of Porto, R. Dr. Roberto Frias, Porto 4200-465, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9981-3826","authenticated-orcid":false,"given":"Maria","family":"Vieira","sequence":"additional","affiliation":[{"name":"CEMUC, Department of Mechanical Engineering, University of Coimbra, R. Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3667-0562","authenticated-orcid":false,"given":"Manuel","family":"Vieira","sequence":"additional","affiliation":[{"name":"CEMUC, Department of Metallurgical and Materials Engineering, University of Porto, R. Dr. Roberto Frias, Porto 4200-465, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2016,4,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1016\/S0966-9795(03)00077-3","article-title":"Infrared brazing of TiAl using Al-based braze alloys","volume":"11","author":"Shiue","year":"2003","journal-title":"Intermetallics"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5273","DOI":"10.1007\/s10853-006-0292-4","article-title":"Investigation into the microstructure and mechanical properties of diffusion bonded TiAl alloys","volume":"41","author":"Bohm","year":"2006","journal-title":"J. Mater. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1007\/BF03220745","article-title":"Ordered intermetallic alloys, Part III: Gamma-titanium aluminides","volume":"46","author":"Kim","year":"1994","journal-title":"JOM"},{"key":"ref_4","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_5","doi-asserted-by":"crossref","first-page":"997","DOI":"10.1016\/S0966-9795(01)00064-4","article-title":"Quo vadis gamma titanium aluminide","volume":"9","author":"Loria","year":"2001","journal-title":"Intermetallics"},{"key":"ref_6","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_7","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1016\/S0921-5093(97)00638-2","article-title":"Joining of TiAl and steels by induction brazing","volume":"239\u2013240","author":"Noda","year":"1997","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1016\/j.msea.2012.11.014","article-title":"Vacuum brazing of TiAl alloy to 40Cr steel with Ti60Ni22Cu10Zr8 alloy foil as filler metal","volume":"561","author":"Dong","year":"2013","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/S1044-5803(02)00319-4","article-title":"Microstructure and strength of diffusion-bonded joints of TiAl base alloy to steel","volume":"48","author":"He","year":"2002","journal-title":"Mater. Charact."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/S1044-5803(03)00122-0","article-title":"A new technology for diffusion bonding intermetallic TiAl to steel with composite barrier layers","volume":"50","author":"He","year":"2003","journal-title":"Mater. Charact."},{"key":"ref_11","first-page":"191","article-title":"Diffusion bonding between TiAl based alloys and steels","volume":"17","author":"Han","year":"2001","journal-title":"J. Mater. Sci. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.msea.2007.08.076","article-title":"Hot pressing diffusion bonding of a titanium alloy to a stainless steel with an aluminum alloy interlayer","volume":"486","author":"He","year":"2008","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2336","DOI":"10.1063\/1.1769097","article-title":"Reactive nanostructured foil used as a heat source for joining titanium","volume":"96","author":"Duckham","year":"2004","journal-title":"J. Appl. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1016\/j.intermet.2005.12.012","article-title":"Nanometric multilayers: A new approach for joining TiAl","volume":"14","author":"Ramos","year":"2006","journal-title":"Intermetallics"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1016\/j.intermet.2005.12.011","article-title":"Solid-state diffusion bonding of gamma-TiAl alloys using Ti\/Al thin films as interlayers","volume":"14","author":"Duarte","year":"2006","journal-title":"Intermetallics"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"225","DOI":"10.4028\/www.scientific.net\/AMR.59.225","article-title":"Joining of superalloys to intermetallics using nanolayers","volume":"59","author":"Ramos","year":"2009","journal-title":"Adv. Mater. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4351","DOI":"10.1007\/s10853-010-4303-0","article-title":"Diffusion bonding of TiAl using Ni\/Al multilayers","volume":"45","author":"Viana","year":"2010","journal-title":"J. Mater. Sci."},{"key":"ref_18","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_19","doi-asserted-by":"crossref","first-page":"678","DOI":"10.1007\/s11665-012-0144-0","article-title":"Microstructure of reaction zone formed during diffusion bonding of TiAl with Ni\/Al multilayer","volume":"21","author":"Viana","year":"2012","journal-title":"J. Mater. Eng. Perform."},{"key":"ref_20","unstructured":"Namazu, T., Takemoto, H., Fujita, H., Nagai, Y., and Inoue, S. (January, January ). Self-propagating explosive reactions in nanostructured Al\/Ni multilayer films as a localized heat process technique for MEMS. Proceedings of 19th IEEE International Conference on Micro Electro Mechanical Systems, Istanbul, Turkey."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhang, J., Wu, F.S., Zou, J., An, B., and Liu, H. (2009, January 10--13). Al\/Ni multilayer used as a local heat source for mounting microelectronic components. Proceedings of the International Conference on Electronic Packaging Technology & High Density Packaging,ICEPT-HDP 09, Beijing, China.","DOI":"10.1109\/ICEPT.2009.5270630"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/j.intermet.2010.10.021","article-title":"Anisothermal solid-state reaction of Ni\/Al nanometric multilayer","volume":"19","author":"Viana","year":"2011","journal-title":"Intermetallics"},{"key":"ref_23","first-page":"73","article-title":"Reaction-assisted diffusion bonding of TiAl alloy to steel","volume":"161","author":"Viana","year":"2016","journal-title":"Mater. Chem. Phys."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7718","DOI":"10.1007\/s10853-013-7592-2","article-title":"Reaction Zone Formed during Diffusion Bonding of TiNi to Ti6Al4V using Ni\/Ti Nanolayers","volume":"48","author":"Viana","year":"2013","journal-title":"J. Mater. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1472","DOI":"10.1126\/science.1161517","article-title":"Imaging of transient structures using nanosecond in situ TEM","volume":"321","author":"Kim","year":"2008","journal-title":"Science"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1564","DOI":"10.1557\/JMR.1992.1564","article-title":"An 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_27","unstructured":"Kipp, D.O. Material Data Sheets. Available online: http:\/\/www.matweb.com."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/j.jpcs.2015.05.019","article-title":"Ab initio studies of the structural, elastic, electronic and thermal properties of NiTi2 intermetallic","volume":"85","author":"Toprek","year":"2015","journal-title":"J. Phys. Chem. Solids"}],"container-title":["Metals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4701\/6\/5\/96\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:22:49Z","timestamp":1760210569000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4701\/6\/5\/96"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,4,25]]},"references-count":28,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2016,5]]}},"alternative-id":["met6050096"],"URL":"https:\/\/doi.org\/10.3390\/met6050096","relation":{},"ISSN":["2075-4701"],"issn-type":[{"value":"2075-4701","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,4,25]]}}}