表面粗糙度对钛合金压力连接界面微观组织与性能的影响  

Effects of Surface Roughness on Microstructure and Mechanical Property of Press Bonding Interface of Titanium Alloy

作　　者：杨舜[1] 于卫新[1] 李宏[1] 李淼泉[1] 

机构地区：[1]西北工业大学材料学院,西安710072

出　　处：《精密成形工程》2017年第4期31-35,共5页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51505386);中国博士后基金(2014M562447)

摘　　要：目的研究表面粗糙度对钛合金压力连接界面微观组织与性能的影响。方法采用压力连接方法,对不同表面粗糙度的TC4合金进行连接试验,观察连接界面处的微观组织形貌,定量分析不同表面粗糙度下,连接界面空洞尺寸与界面结合率的变化规律,通过剪切试验,测定连接界面的剪切强度,并观察剪切断口形貌。结果在连接温度为850℃、连接压力为30 MPa、连接时间为10 min的条件下,连接表面粗糙度Ra由0.34μm减小至0.12μm时,连接界面处的空洞逐渐由尺寸较大的长条状转变为微小的圆形空洞,空洞完全消失的区域逐渐增多;平均空洞尺寸由2.7μm减小至1.4μm,连接界面结合率由88.2%提高至94.6%;连接界面剪切强度由682 MPa增大至762 MPa,剪切断口呈现韧性断裂特征的区域显著增大。结论表面粗糙度对钛合金压力连接界面微观组织和剪切强度影响显著,降低表面粗糙度有利于提高钛合金压力连接质量。The paper aims to study effects of surface roughness on microstructure and mechanical property of press bonding interface of titanium alloy. C4 alloy with different surface roughness was tested with the press bonding method. The microstructure of bonding interface was investigated, and the variation of interfacial void size and bonding ratio with surface roughness was quantificationally analyzed. The shear strength of bonding interface was measured by shearing test and the fracture surface morphology was observed. At 850 ℃, 30 MPa and 10 min, the interfacial voids with a strip shape and an average size of 2.7 μm changed to the voids with a round shape and an average size of 1.4μm as the surface roughness Ra decreased from 0.34 μm to 0.12μm. The bonding ratio increased from 88.2% to 94.6% while the shear strength of bonding interface increased from 682 MPa to 762 MPa. The area of fracture surface exhibiting ductile fracture characteristics evidently increased. Surface roughness has significant influences on the microstructure and shear strength of press bonding interface of titanium alloy. Decreasing of surface roughness is helpful to improve the bonding quality of titanium alloy.

关 键 词：钛合金 压力连接 表面粗糙度 微观组织 剪切强度 

分 类 号：TG453[金属学及工艺—焊接]