强流脉冲电子束能量密度对TiAlN涂层微观组织和硬度的影响  

Microstructure and Microhardness of TiAlN Coatings with Different Energy Densities of High Current Pulsed Electron Beam

作　　者：芦馨[1] 金光[1] 高景龙[1] 吕逍[1] 娄长胜[1] 王强 

机构地区：[1]沈阳理工大学材料科学与工程学院,辽宁沈阳110159 [2]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110819

出　　处：《稀有金属》2016年第5期453-459,共7页Chinese Journal of Rare Metals

基　　金：国家科技重大专项项目(2012ZX04003-061)资助

摘　　要：采用不同能量密度的电子束对硬质合金刀具Ti Al N涂层进行轰击处理,研究了电子束能量密度对Ti Al N涂层表面改性后的微观组织和硬度的影响。利用扫描电镜(SEM)、能谱分析(EDS)、X射线衍射仪(XRD)分别对Ti Al N涂层进行表面形貌观察、元素分析和物相分析,并对涂层表面进行粗糙度和显微硬度测试。结果表明,随着能量密度的增加,涂层表面更趋于致密。在相同的能量密度1.75 J·cm^(-2)下,采用相对较低的阴极加速电压7 k V和较高电流强度130 A轰击时,涂层表面粗糙度最低达0.15μm。经电子束轰击后的Ti Al N相衍射峰相对强度有所提高;涂层相衍射峰不同程度地向高角度偏移,并且同样能量密度条件下加速电压越高,偏移角度越大;同时涂层相衍射峰有一定宽化趋势。表明电子束轰击后Ti Al N涂层产生较大的压应力和热应力,使晶粒细化,并且在一定的热应力驱动下有利于原子扩散,形成较宽的过渡层,从而提高涂层和基体间结合力。显微硬度随着能量密度的增加呈上升趋势,而相同的能量密度条件,加速电压的提高有助于涂层表面硬化。TiAlN coated carbide tools were irradiated by high current pulsed electron beam with different energy densities and the in- fluences of energy densities on microstructure and microhardness of TiAlN coating were investigated. The morphology was observed by scanning electron microscope （SEM）, the element distribution and the phase composition of coatings were analyzed by energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）, respectively, and the roughness and microhardness of coatings were also measured. The results showed that the surface of irradiated TiAlN coatings became denser with the increase of energy densities. At the same energy density of 1.75 J·cm^-2, the lowest roughness value was 0.15 μm as irradiated with lower volt of 7 kV and higher current of 130 A. The intensity of diffraction peaks of TiAlN phase became higher than that of untreated ones. The diffraction peaks of phases deviated irregularly towards higher angles and the higher accelerating voltage made the greater deviation with the same energy density employed; meanwhile, the diffraction peaks were widen. It implied that higher compressive and thermal stress in irradiated coatings refined the grains. Furthermore, higher thermal stress drove the atoms to diffuse to form wider transition layer, which improved the adhesion of coating and substrate. Microhardness was enhanced with the increase of energy densities, and the hardness increased with the rise of accelerating volt on the condition of the same energy density.

关 键 词：电子束 能量密度 TIALN涂层 粗糙度 显微硬度 

分 类 号：TG178[金属学及工艺—金属表面处理] TG712[金属学及工艺—金属学]