取向匹配性对DD6单晶接头持久性能的影响

Effect of crystal orientation matching on stress-rupture property of DD6 single crystal joint

对4种不同晶体取向组合的DD6单晶试样进行了TLP扩散焊,包括连接面垂直或平行于单晶生长方向,二连接试样取自同一单晶试样且二者的晶体取向完全匹配或二连接试样取自不同单晶试样即二者的晶体取向有一定差别,并测试了接头持久性能.结果表明,连接试样的晶体取向对接头持久性能影响不明显,但其匹配性对接头持久性能有较大影响.当二连接试样的晶体取向完全匹配时,可获得单晶化的接头,其持久性能可达到DD6单晶母材的90%以上.而当二连接试样的晶体取向有差别时,由于在焊缝中心形成了连续的界面,接头持久性能测试结果则很分散.

Four types of DD6 single crystal joints with different crystal orientation combination,the bonding surfaces perpendicular or parallel to the principle axis of the single crystal and the crystal orientations of the two bonded pieces completely matched or with some misorientation,were obtained by transient liquid phase(TLP) diffusion welding.The result of testing the stress-rupture property of the joints showed that the crystal orientation of the bonded pieces had little effect on the joint properties,but their matching relationship affected the joint properties.When the two pieces had completely matched crystal orientations,the joints possessed the optimum stress-rupture property which surpassed 90% of the DD6 base metal.When there was difference between the crystal orientations of the two bonded pieces,the results of the joint stress-rupture property test were scattered.