Al含量和烧结温度对Ti_(50)Ni_(50)与Ti_(47)Ni_(47)Al_6合金耐蚀性的影响

采用粉末冶金方法制备了Ti_(50)Ni_(50)与Ti_(47)Ni_(47)Al_6合金,通过极化曲线、配备能谱分析的扫描电镜测试手段研究了Al含量和烧结温度对烧结合金耐蚀性的影响。结果表明:1080℃烧结Ti_(50)Ni_(50)合金表现为钝化特征,蚀孔尺寸较小,弥散分布;Al含量为6%时,合金表现为活性溶解,蚀孔尺寸及腐蚀区域面积显著增加,耐蚀性降低;烧结温度提高至1180℃时,合金重新表现为钝化,蚀孔尺寸及腐蚀区域面积显著减小,耐蚀性最佳。

Effects of Al Content and Sintering Temperature on the Corrosion Resistance of Ti50Ni50 and Ti47Ni47Al6 Alloys

Ti50Ni50 and Ti47Ni47Al6 alloys were prepared by the powder metallurgy method, and effects of Al content and sintering temperature on the corrosion resistance of sintered alloys were investigated by polarization curves and scanning electron microscope equipped with an energy dispersive X-ray. The results indicate that Ti50Ni50 alloy sintered at 1080 °C exhibits passivation behavior and etch pits disperse with small sizes. The alloy presents active dissolution behavior at Al content of 6%; at the same time the size of etch pits and the corrosion area increase and its corrosion resistance decreases. With the sintering temperature increasing to 1180 °C, the Ti47Ni47Al6 alloy transforms to passivation behavior again, the size of etch pits and the corrosion area dramatically decrease and its corrosion resistance is the best