聚焦光束钎焊接头的力学性能及变形行为

Mechanical Properties and Deformation Behavior of Light Beam Brazing Joint

研究了光束钎焊获得的对接和搭接钎焊接头的力学性能及其在拉伸载荷作用下的变形行为 .光束钎焊对接接头的断裂强度 σb、相对延伸率 δ、断面收缩率 ψ均低于被钎焊母材 .同质接头的弹性极限σ0 .0 1、屈服极限σ0 .2 与母材相当 ,而异质接头的σ0 .0 1、σ0 .2 值仅取决于低屈服极限的母材 ,与高屈服极限的母材无关 .对接接头在拉伸载荷作用下的变形是非均匀的 ,同质接头中的钎缝和近缝区的塑性变形量最小 ,而异质接头中屈服极限较高的母材一侧几乎无塑性变形 .搭接接头在拉伸载荷作用下会产生“折弯效应”,折弯程度随被钎焊母材屈服极限的增加而减小 .对接接头的断裂是由纯拉应力导致的 ,而搭接接头的断裂是剪应力和拉应力综合作用的结果 .

The mechanical properties and deformation behavior of light beam brazing butt and lap joints were investigated by tension test. The breaking strength σb, relative elongation δ and fracture' surface shrinkage ψ of butt joint by light beam brazing are lower than those of brazed base material. The elastic limit σ0.01 and yield limit σ0.2 of similar materials joint are similar to those of base material, while those properties of dissimilar materials joint only lie on the base material with lower yield limit. When tension load acts on the but joint, the similar material joint deforms unevenly and the plastic deformation levels of brazing seam and HAZ are the least, while the base material with higher yield limit of dissimilar material joints hardly deforms plastically. The lap joint produces bending effect under the action of tensile load and the bending degree decreases with the increase of yield limit of base material. The fracture of butt joints results from the pure tension stress, while the fracture of lap joints is the corporate result of shear stress and tension stress.