A356浇覆温度对铝/钢复合板界面组织及力学性能的影响

先采用热浸镀铝?锌工艺对Q235钢板进行表面镀层处理,后将液态的A356铝合金定量浇覆于经预热的钢板表面,通过液固铸轧成功制备铝/钢复合板。运用光学显微镜(OM)、SEM观察界面结合与组织形貌,结合EDS、XRD分析界面物相成分,并测试微观硬度、室温拉伸和剪切强度。结果表明:随着浇覆温度的提高,复合板界面间隙消失,整体趋势上扩散层厚度逐渐增加。当浇覆温度为710℃及以上时,界面处会形成Fe3Al、FeAl、FeAl2、Fe2Al5和FeAl3相。在同一浇覆温度下,硬度整体趋势为在Q235和A356基体中保持稳定,而在从Q235侧距界面中心100μm至A356侧距界面中心100μm的范围内连续下降。抗拉强度和剪切强度都表现出先增加后减小的趋势,浇覆温度为710℃时,复合板的成形质量最佳,抗拉强度和剪切强度都为最大,分别为336.4 MPa和137.6 MPa。

Effect of A356 alloy covering temperature on microstructure and mechanical properties of Al/low-carbon steel clad plates

The hot-dip aluminizing-zinc process was used to pre-treat the low-carbon steel plates,and then the aluminum/low-carbon steel clad plates were successfully fabricated by liquid-solid twin-roll casting(LSTRC).The microstructure observation and interface combination of the clad plates were investigated by optical microscope(OM)and scanning electrical microscope(SEM),and the phase composition was measured by energy dispersive spectrometer(EDS)as well as X-ray diffractometer(XRD).In addition,with the mechanical properties of the clad plates were characterized by microhardness,room temperature tensile and shear tests.The results show that the interface gaps of the clad plates disappear and the overall trend of the thickness of the diffusion layer gradually increase when the covering temperature increasing.In the LSTRC process,when the pouring temperature is 710℃and above,Fe3Al,FeAl,FeAl2,Fe2Al5 and FeAl3 phases are formed at the interface.At the same covering temperature,the overall microhardness trend is stable in the Q235 and A356 substrates,and the microhardness decreases continuously from Q235 side distance interface center about 100μm to A356 side distance interface center about 100μm.The tensile strength and shear strength of the clad plates increase firstly and decrease later.When the A356 covering temperatures is 710℃,the tensile strength and shear strength reach the highest value,which are 336.4 MPa and 137.6 MPa,respectively.