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铸造-倾析-铸造技术是近年来发展起来的一种制备功能梯度材料的新方法。采用这种方法制备在径向具有梯度功能的圆柱形试样,其外表层为具有高耐磨性的A390铝合金,芯部为具有较高韧性和加工性能的A356铝合金。研究芯部熔体在不同过热温度(750,820和860°C)和表层在不同倾析时间(25,35和45 s)下的A390/A356合金界面接合情况。采用光学显微镜和扫描电镜对界面进行表征,对界面区的显微硬度进行测量。结果表明,在过热温度为860°C,倾析时间为35 s的条件下,可以获得一宽度约为500μm的接合良好的界面层。比较了试样表面层和芯部的耐磨性能。
Casting - Decanter - Casting technology developed in recent years, a new method for the preparation of functionally graded materials. In this way, a cylindrical specimen with gradient function in radial direction was prepared. Its outer surface was A390 aluminum alloy with high wear resistance, and the core was A356 aluminum alloy with higher toughness and machinability. The interfacial bonding of A390 / A356 alloy with core melt under different superheat temperatures (750, 820 and 860 ° C) and surface decay times (25, 35 and 45 s) was investigated. The optical microscopy and scanning electron microscopy were used to characterize the interface and the microhardness of the interface was measured. The results show that under the condition of overheating temperature of 860 ° C and decanting time of 35 s, a well-bonded interface layer with a width of about 500 μm can be obtained. The wear resistance of the sample surface layer and core is compared.