不同取向DD3单晶合金扩散连接接头组织及性能

采用D1F非晶态箔中间层合金对0°+30°,0°+60°取向组合的DD3单晶合金试样进行了TLP扩散焊,研究了被焊单晶合金试样相互之间的取向对接头组织和性能的影响.结果表明:当被焊二母材取向不一致时,由于在焊缝中央存在较大块状γ′相组成的界面,且此界面与外加应力方向垂直,是高温应力作用下的薄弱环节,从而使接头持久性能明...

Microstructures and Properties of DD3 Single Crystal Alloy Joints with Different Orientation

The DD3 single crystal alloy specimens with the orientation combination of 0°+30°and 0°+60° were TLP diffusion bonded with D1F amorphous foil interlayer alloy.The effect of the crystal orientation between the two bonded single crystal alloy specimens on the microstructure and property of the joint was investigated.The results showed that,in the middle part of the joint bonded by two specimens with different crystal orientations,there existed a boundary composed of γ′phases in the form of large block,which was vertical to the applied stress and so became the weak part of the joint.As a consequence,the stress-rupture property of the joint was below to 40% of that of the base material,and all of the test specimens fracture at the bonding seam.However,using the same interlayer alloy and the same bonding parameters,the joint formed by two specimens with the same crystal orientation exhibited homogeneous microstructures,and the stress-rupture property of the corresponding joint was comparable to that of the base material.So in order to obtain the joints of high property,it should make the two bonded specimens with the same orientations as more as possible.