【摘要】 采用纯镍中间夹层和激光焊技术,连接TiNi形状记忆合金丝和不锈钢丝异种材料。对比分析了加镍夹层与未加镍夹层的激光焊接头的组织和性能。结果表明,与未加镍夹层的接头相比,加镍夹层的接头组织和性能得到明显改善,接头组织中γ-Fe相含量增加,TiFe2,TiCr2等金属间化合物相含量减少,焊缝区硬度明显降低,接头抗拉强度提高。未加镍夹层的接头的抗拉强度仅为187MPa,断口呈现典型的脆性断裂特征。加镍夹层后,接头抗拉强度提高至372MPa,断口具有脆-韧混合型断裂特征。更多还原

【Abstract】 TiNi shape memory alloy and stainless steel wires were butt joined by laser welding with pure Ni interlayer.Microstructures and properties of joints with and without Ni interlayer were analyzed and discussed.The results showed that microstructures and properties of the joint with Ni interlayer were improved significantly compared with the joint without Ni interlayer.More γ-Fe phase and less intermetallic compounds such as TiFe2,TiCr2 were formed in the joint with Ni interlayer,which led to the decrease of weld microhardness and increase of joint strength.The joint strength without Ni interlayer was only 187MPa and the corresponding fracture surface exhibited a typical brittle feature.Using the Ni interlayer elevated joint strength to 372MPa and changed the joint fracture mode from pure brittle feature to mixture of cleavage and dimples.更多还原