Ultrasonic Spot Welding of Aluminum to High-Strength Low-Alloy Steel: Microstructure, Tensile and Fatigue Properties
Ultrasonic Spot Welding of Aluminum to High-Strength Low-Alloy Steel: Microstructure, Tensile and Fatigue Properties
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DOI：
10.1007/s11661-013-2123-y
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发表时间：
2014-04-01
影响因子：
2.8
通讯作者：
Chen, D. L.
中科院分区：
文献类型：
--
作者：
Patel, V. K.;Bhole, S. D.;Chen, D. L.
轻质铝合金的结构应用不可避免地涉及与钢的异种焊接以及相关的耐久性问题。本研究旨在评估铝-镀锌高强度低合金（HSLA）钢异种超声波点焊接头的显微组织变化、搭接剪切拉伸载荷和抗疲劳性能。通过 SEM/EDS 和 XRD，在 Al 和 HSLA 钢之间发现了两个不均匀层。一个是 Al-Zn 共晶层，另一个是熔核区中 Al 和 Fe 的金属间化合物 (IMC) 薄层（< 2 μm）。搭接剪切拉伸测试给出的最大载荷为 3.7 kN，样品首先在 Al-Zn 共晶膜和 Al-Fe IMC 之间失效，随后在两个匹配断裂表面上含有 Al 的区域失效。疲劳测试结果显示疲劳极限约为 0.5 kN（1 x 10(7) 循环）。疲劳断裂从横向全厚度裂纹扩展模式向界面失效模式转变时的最大循环应力随着能量输入的增加而增加。
The structural applications of lightweight aluminum alloys inevitably involve dissimilar welding with steels and the related durability issues. This study was aimed at evaluating the microstructural change, lap shear tensile load, and fatigue resistance of dissimilar ultrasonic spot-welded joints of aluminum-to-galvanized high-strength low-alloy (HSLA) steel. Two non-uniform layers were identified in between Al and HSLA steel via SEM/EDS and XRD. One was an Al-Zn eutectic layer and the other was a thin (< 2 mu m) layer of intermetallic compound (IMC) of Al and Fe in the nugget zone. The lap shear tensile testing gave a maximum load of 3.7 kN and the sample failed initially in between the Al-Zn eutectic film and Al-Fe IMC, and afterward from the region containing Al on both matching fracture surfaces. The fatigue test results showed a fatigue limit of about 0.5 kN (at 1 x 10(7) cycles). The maximum cyclic stress at which transition of the fatigue fracture from transverse through-thickness crack growth mode to the interfacial failure mode occurs increases with increasing energy input.