TC4钛合金表面B-Al复合渗层的组织和性能  

Microstructure and properties of B-Al composite coatings on TC4 titanium alloy

作　　者：高顺 田晓东[1] 张梦瑶 Gao Shun;Tian Xiaodong;Zhang Mengyao(School of Materials Science and Engineering,Chang'an University,Xi'an Shaanxi 710064,China)

机构地区：[1]长安大学材料科学与工程学院,陕西西安710064

出　　处：《金属热处理》2020年第3期11-14,共4页Heat Treatment of Metals

摘　　要：采用固体粉末包埋渗两步法,在TC4钛合金表面先1050℃渗硼4~6 h再950~1050℃渗铝4 h制备出B-Al复合耐磨渗层。利用X射线衍射仪(XRD)、扫描电镜(SEM)、波谱仪(WDS)和能谱仪(EDS)、显微硬度仪和摩擦磨损试验机对复合渗层的物相组成、显微组织、微区成分、表面硬度和摩擦因数进行测试和分析。结果表明:B-Al复合渗层厚为37~115μm,主要由TiB2相和TiAl3相组成,外层是弥散分布TiB2的TiAl3层,向内依次形成厚度较小的TiAl2、TiAl及Ti3Al等Ti-Al金属间化合物层。B-Al复合渗层表面硬度为1041.7~1429.4 HV0.1,约为TC4钛合金硬度的3.03~4.16倍;经1050℃×6 h渗B后1050℃×4 h渗Al,其摩擦因数约为0.3,较TC4钛合金基体下降约25%。B-Al composite coatings were prepared on the surface of TC4 titanium alloy by boronizing at 1050℃for 4-6 h and subsequent aluminizing at 950-1050℃for 4 h through a two-step pack cementation process.The constituent phases,microstructure,composition,hardness,friction coefficient of the composite coatings were analyzed by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),wavelength dispersive spectrometer(WDS)and energy dispersive spectrometer(EDS),microhardness tester,and friction and wear tester.The results show that the thickness of the B-Al composite coatings is in the range of 37-115μm,and the coatings mainly consist of TiB2 and TiAl3 phases.The outer layer is TiAl3 layer with dispersed TiB2;and TiAl2,Ti Al and Ti3Al intermetallic compound layers with smaller thickness are formed inward in turn.The surface hardness of the B-Al composite coatings is in the range of 1041.7-1429.4 HV0.1,which is about 3.03-4.16 times of the TC4 alloy.By boronizing at 1050℃for 6 h followed by aluminizing at 1050℃for 4 h,the friction coefficient of the B-Al composite coating is about 0.3,lower than that of TC4 alloy by about 25%.

关 键 词：TC4钛合金 B-Al复合渗层 摩擦因数 耐磨性能 

分 类 号：TG174.445[金属学及工艺—金属表面处理]