液体中脉冲放电制备(Ti,Al)C陶瓷涂层的研究

用粉末模压成型工艺和无压烧结方法制备了Ti-Al混合烧结工具电极,采用所制备的电极在煤油中对45钢表面进行脉冲放电沉积(Ti,Al)C陶瓷涂层。探讨了粉体配比对工具电极致密度和相组成以及对液相放电所制备的涂层组织与表面形貌的影响。结果表明,随着Al含量的提高,工具电极密度和相对密度先下降后升高,当Al含量为60%时,电极密度达到最小;XRD结果显示制备出涂层的物相主要为(Ti,Al)C,而制备出的涂层表面形貌明显不同,随着电极中Al元素的升高,熔滴状的熔池尺寸越来越大,宏观上越来越粗糙,截面涂层厚度约为20μm。

(Ti,Al)C ceramic coating prepared by electrical discharge in liquid

Ti-Al powder sintered tool electrodes were prepared by mould pressing and pressureless sintering method,and the ceramic coating was prepared with the tool electrode on the surface of 45 steel by electrical discharge coating in kerosene.Effect of the powder composition on density of the tool electrode and phase composition,microstructure and surface morphology of the prepared coatings were studied.The results show that as the aluminum content increases,the density and the relative density of the Ti-Al sintered tool electrodes decrease markedly first then increase.The density reaches the lowest as the aluminum content is 60%.The XRD results show that the phase constituent of the coating is mainly(Ti,Al)C and the morphologies of the coating are obviously different.With the increase of aluminum content,the size of the molten drop-like melt pool increases,and the surface roughness increases in macroscopic view.The thickness of the coating is about 20 μm.