Laser brazing was carried out for dissimilar joining of sialon and a WC–Co alloy. Eutectic type Ag–Cu alloys as filler metals with different Ti content ranging from 0 to 2·8 mass-% were used to investigate the effects of Ti on the interface structure and strength of the joint. The filler metal sheet was sandwiched between a sialon block and a WC–Co alloy plate, and a laser beam was irradiated selectively on the WC–Co alloy plate. The brazed joint was obtained using the filler metal containing >0·3 mass-%Ti. TiN, Ti5Si3, and Cu4Ti layers were formed at the interface of sialon and brazed metal as compound layers. The shear strength of the brazed joint increased with increasing Ti content in the filler metal in the range 0·3–1·7 mass-%, reaching a maximum value of 106 MPa. However, the strength decreased when the Ti content became higher than 1·7 mass-%.
LiuCF, ZhangJ, ZhouY, MengQC and NakaM: ‘Effect of Ti content on microstructure and strength of Si3N4/Si3N4 joints brazed with Cu-Pd-Ti filler metals’, Mater. Sci. Eng. A, 2008, A491, 483–487.
2.
LiuGM, ZouGS, WuAP and ZhangDK: ‘Improvements of the Si3N4 brazed joints with intermetallics’, Mater. Sci. Eng. A, 2006, A415, 213–218.
3.
HeYM, ZhangJ, LiuCF and SunY: ‘Microstructure and mechanical properties of Si3N4/Si3N4 joint brazed with Ag–Cu–Ti–SiCp composite filler’, Mater. Sci. Eng. A, 2010, A527, 2819–2825.
4.
ZhangJ, HeYM, SunY and LiuCF: ‘Microstructure evolution of Si3N4/Si3N4 joint brazed with Ag-Cu-Ti-+SiCp composite filler’, Ceram. Int., 2012, 36, 1397–1404.
5.
AbedA, JalhamIS and HendryA: ‘Wetting and reaction between β′-sialon, stainless steel and Cu-Ag brazing alloys containing Ti’, J. Eur. Ceram. Soc., 2001, 21, 283–290.
6.
ShichiY, AritaM and MatsunagaM: ‘Study of joining interface between Si3N4 and Ag-Cu-Ti active metal’, J. Ceram. Soc. Jpn, 1988, 96, (9), 930–934.
7.
ShibayanagiT: ‘Joining of ceramics’, J. Jpn. Weld. Soc., 2010, 79, (7), 27–33.
8.
KimuraM, AsariK, GotoS and AsoS: ‘Residual stress and bonding strength in the electrical sialon ceramics joint made by using the brazing metal layer’, Int. J. Soc. Mater. Eng. Res., 2002, 10, (1), 81–87.
9.
XianA and SiZ: ‘Behaviour of buffer layer in joining of sialon ceramics to steel 40Cr’, Acta Metall. Sin. B, 1992, 5B, (3), 201–205.
10.
LeeHK and LeeJY: ‘A study of the wetting, microstructure and bond strength in brazing SiC by Cu-X (X = Ti, V, Nb, Cr) alloy’, J. Mater. Sci., 1996, 31, 4133–4140.
11.
SechiY, TakezakiA, MatsumotoT, TsumuraT and NakataK: ‘Composition dependence of titanium in silver-copper-titanium alloy braze on dissimilar laser brazing of boron nitride ceramics and cemented carbide’, Mater. Trans., 2009, 50, (6), 1294–1299.
12.
SechiY, TsumuraT and NakataK: ‘Dissimilar laser brazing of boron nitride and tungsten carbide’, Mater. Des., 2010, 31, 2071–2077.
13.
NagatsukaK, SechiY, MiyamotoY and NakataK: ‘Characteristics of dissimilar laser-brazed joints of isotropic graphite to WC–Co alloy’, Mater. Sci. Eng. B, 2012, 177B, 520–523.
14.
SudmeyerI, HettesheimerT and RohdeM: ‘On the shear strength of laser brazed SiC–steel joints: effects of braze metal fillers and surface patterning’, Ceram. Int., 2010, 36, 1083–1090.
15.
KlockeF and FrankS: ‘Surface deposits in laser brazing’, Sci. Technol. Weld. Join., 2013, 18, (1), 62–69.
16.
XianAP: ‘Joining of sialon ceramics by Sn–5at%Ti based ternary active solders’, J. Mater. Sci., 1997, 32, 6387–6393.
17.
NomuraM, IchimoriT, IwamotoC and TanakaS: ‘Structure of wetting front in the Ag-Cu-Ti/SiC reactive system’, J. Mater. Sci., 2000, 35, 3953–3958.
18.
PetevesSD, CecconeG, PaulastoM, StamosV and YvonP: ‘Joining silicon nitride to itself and to metals’, JOM, 1996, 48, 48–52.
19.
KimuraM, AsariK, GotoS and AsoS: ‘Residual stress distribution in electrical ceramics/metal joint’, Q. J. Jpn Weld. Soc., 2003, 21, (3), 448–459.
20.
NakaoY, NishimotoK, SaidaK and OhishiT: ‘Effect of reaction layer on bonding strength of Si3N4 to metals – factors affecting bonding strength of fine ceramics to metals (Report 1)’, Q. J. Jpn Weld. Soc., 1993, 11, (1), 142–148.
21.
NakaoY, NishimotoK, SaidaK and OhishiT: ‘Improvement in bonding strength of Si3N4 to metals joints by controlling reaction layer thickness – factors affecting bonding strength of fine ceramics to metals (Report 2)’, Q. J. Jpn Weld. Soc., 1993, 11, (2), 294–300.
22.
WangY, QiuXM, SunDQ and YinSQ: ‘Influence of Ti on microstructure and strength of c-BN/Cu-Ni-Sn-Ti composites’, Int. J. Refract. Met. Hard Mater., 2011, 29, 293–297.
23.
LiuY, HuangZR and LiuXJ: ‘Joining of sintered silicon carbide using ternary Ag-Cu-Ti active brazing alloy’, Ceram. Int., 2009, 35, 3479–3484.
