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采用双辉等离子表面合金化技术在Ti6Al4V合金表面制备镍合金层,采用SEM、GDOES以及XRD对比研究了温度和放电气压对镍合金层结构、成分分布和相组成的影响。结果表明:镍合金层由3层结构组成,从外向内依次是单质镍的镍沉积层,主要化合物为Ni3Ti、Ti2Ni、NiTi、AlNi3的富镍合金层和贫镍合金层。不同温度和气压条件下,合金化试样表面呈现“胞状凸起”形貌。随着温度升高,表面晶粒长大,孔洞减少,间隙减小;富镍合金层和贫镍合金层厚度增加,镍沉积层厚度先增后减。随着气压增大,表面晶粒变细,孔洞增多,间隙增加;镍沉积层和富镍合金层厚度减少,贫镍合金层厚度先增后减。基体晶粒长大的临界温度存在于900~930℃之间。
The nickel alloy layer was prepared on the surface of Ti6Al4V alloy by double glow plasma surface alloying. The effects of temperature and discharge pressure on the structure, composition distribution and phase composition of the nickel alloy were studied by SEM, GDOES and XRD. The results show that the nickel alloy layer is composed of three layers. From the outside to the inside, the nickel layer is a single layer of nickel. The main compounds are nickel-rich alloy layer and nickel-poor alloy layer of Ni3Ti, Ti2Ni, NiTi and AlNi3. Under different temperature and pressure conditions, the surface of the alloyed specimen showed “cell bulge” morphology. With the increase of temperature, the surface grain grows, the holes decrease and the gap decreases. The thickness of nickel-rich alloy layer and lean nickel alloy layer increases, and the thickness of nickel deposit layer increases first and then decreases. With the increase of pressure, the grains on the surface become thinner, the number of holes increases and the gap increases. The thickness of nickel deposit and nickel-rich alloy decreases and the thickness of lean nickel alloy increases first and then decreases. The critical temperature at which the matrix grains grow is between 900 and 930 ° C.