摘要
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。
Influences of temperature and discharge pressure on Ni alloying layers of Ti6Al4 V alloy prepared by plasma surface alloying technology were studied. The SEM,GDOES,and XRD were used to investigate the microstructure,composition distributions and the phases of the Ni alloying layers. The results show that the Ni alloying layer consists of triple layers structure. From the surface to the matrix,they are Ni deposition layer containing the elemental Ni,Ni-rich alloying layer including the phases of Ni3 Ti,Ti2Ni,NiTi,AlNi3 and Ni-poor alloying layer. Under the different temperatures and discharge pressures,the morphology of the alloying samples is'cellular protrusions'. With temperature increasing,the surface grain sizes grow,the surface pores and the grain gaps decrease; the Ni-poor alloying layers and the Ni-rich alloying layers thicken,and the thickness of the Ni deposition layers firstly increases and then decreases.With increasing discharge pressures,the surface grain sizes become smaller,the surface pores and the grain gaps increase; the Ni deposited layers and Ni-rich alloying layers become thin,and the thickness of the Ni-poor alloying layers firstly increases and then decreases. The critical temperature of the matrix grain growth is between 900-930 ℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2014年第10期161-166,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51071106)
山西省自然科学基金(2012011021-4
2013011012-4)
山西省回国留学人员科研资助项目(2013-048)
