双层辉光等离子技术提高TC4合金阻燃性能

叙述了采用双层辉光等离子渗金属技术,在TC4合金表面渗入Cr元素,形成Ti-Cr阻燃合金层。结果指出,Ti-Cr阻燃合金层中Cr元素呈梯度分布,在距离表面70μm的深度范围内,Cr含量均超过20%。阻燃合金层的显微组织为基体组织加少量弥散分布的点状Cr2Ti金属间化合物,大部分Cr元素固溶于β相中,阻燃合金层与基体结合良好,TC4渗Cr后的比磨损率降低到基体的20%,激光点燃温度相对基体的提高大于500℃,阻燃性能有较大幅度的提高。

Study on Flame Retardant TC4 Modified by Double Glow Plasma Surface Chromizing

A coating was prepared on TC4 surface by double glow plasma surface chromizing technique in order to improve the capability of its flame retardancy.It shows that the microstructure of the surface coating was the mixture of Cr 2Ti and TC4 matrix,and Cr2 Ti was dispersed in TC4 matrix with most Cr dissolving in the β phase.The weight fraction of Cr exceeded 20% within the depth of 70μm.The coating combined well to the matrix.The characterization of flame retardancy was also investigated.The wear rate was decreased to 20% compared with TC4,and the laser ignition temperature was improved more than 500 ℃ after surface chromizing.