压印接头典型失效形式及机理

Typical Failure Modes and Mechanisms of Clinched Joints

选取1420铝锂合金(1420)和镀锌钢进行不同组合压印连接,对所得接头进行静态力学性能试验,并运用扫描电子显微镜对接头拉伸断口进行微观分析。结果表明:镀锌钢-1420接头的静拉伸强度和能量吸收值最大(3 119.3 N,4.757 J);1420-1420接头最小(2 243.4 N,0.598 J)。1420-1420接头为颈部断裂失效,镀锌钢-镀锌钢接头为混合失效,两种接头同时存在韧性断裂和脆性断裂两种特征;镀锌钢-1420接头为上板拉脱失效,接头断口为韧性断裂。

Selecting 1420 aluminum lithium alloy and galvanized steel,the technology of clinching was applied to join the single lap-jointed joints in different sequence. The static mechanical behavior text were carried out to examine the mechanical behavior of 1420- 1420,galvanized steel- 1420 and galvanized steel-galvanized steel joints. Scanning electron microscope was used to analyze the tensile fracture of the joints. It can be seen from experiments that the tensile-shear strength and energy absorption of galvanized steel- 1420 joint are the biggest（ 3 119.3 N,4.757 J）,and much greater than that of 1420- 1420 joints（ 2 243.403 N,0.598 J）. The failure modes of 1420- 1420 joints are neck-fracture,the failure modes of galvanized steel-galvanized steel joints are mixed failure. Microscopic analysis showed that the two type of joints both had cleavage and dimple morphological features. The failure modes of galvanized steel- 1420 joints are button separation,the fracture of joints are ductile fracture.