钛合金渗碳处理研究进展  

Research Progress in Carburizing Treatment of Titanium Alloys

作　　者：庄唯 王耀勉[1] 杨换平 剡文斌 ZHUANG Wei;WANG Yaomian;YANG Huanping;YAN Wenbin(School of Metallurgical Engineering,Xi an University of Architecture and Technology,Xi an 710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院,西安710055

出　　处：《材料导报》2020年第S02期344-347,355,共5页Materials Reports

基　　金：陕西省重点研发计划(2017GY-115)。

摘　　要：钛及钛合金在航空航天、汽车轮船、国防工业、医疗等领域的应用越来越广泛,对其性能要求越来越高。但是钛及钛合金硬度较低、摩擦磨损性能较差,使其在摩擦学领域的应用受到很大限制。利用渗碳处理工艺在钛合金表面形成渗碳层,可明显提高钛合金表层硬度和摩擦磨损性能。本文综述了当前钛合金渗碳处理所采用的气体渗碳、激光渗碳和等离子渗碳三种渗碳工艺,以及相应的渗碳机理和渗碳层微观结构特征。其中钛合金气体渗碳主要以CO、甲烷作为碳源,通过气固相界面传输,使活性碳原子扩散到钛合金的表层及次表层,并形成TiC层,是相对经济的渗碳方式;气体渗碳时钛合金完全暴露在大气中,由于氧与钛的亲和力较高容易形成致密的氧化层,阻碍碳原子的进一步扩散。激光渗碳方法在钛合金表面原位生成TiC。激光渗碳时仅熔化部分材料,引入能量较小,得到的渗碳层组织均匀,韧性较高,而且与基体结合力强。等离子渗碳在阴极和阳极电离作用下使碳离子撞击钛合金表层形成渗碳层。等离子渗碳时的真空处理条件避免了氧化膜的形成和氢元素进入基体后所造成的氢脆现象。等离子渗碳获得的渗碳层较深、TiC浓度较高,而且渗碳周期短。本文比较了钛合金三种不同渗碳工艺之间的异同,并对钛合金渗碳处理的研究提出了展望。Titanium and titanium alloy are widely used in aerospace,automobile and ship,national defense industry,medical treatment and other fields.However,the low hardness,poor friction and wear properties of titanium and its alloy restrict their application in tribology.The carburized layer on the surface of titanium alloy can obviously improve the surface hardness and friction and wear performance of titanium alloy.In this paper,three carburizing processes,gas carburizing,laser carburizing and plasma carburizing,as well as corresponding carburizing mechanism and microstructure characteristics of carburizing layer,are summarized.The gas carburizing of titanium alloy mainly uses CO and methane as carbon sources.Through gas-solid interface transmission,activated carbon atoms diffuse to the surface and subsurface layer and form TiC layer,which is a relatively economic carburizing method.During gas carburizing,titanium alloy is completely exposed to the atmosphere,and dense oxide layer is easily formed due to the high affinity between oxygen and titanium,which hinders the further diffusion of carbon atoms.TiC was generated in situ on the surface of titanium alloy by laser carburizing.During laser carburizing,only part of the material is melted,therefore the energy consumption is small.The carburizing layer can show uniform microstructure,high toughness,and high adhesion strength with the matrix.Plasma carburizing causes carbon ions to collide with titanium alloy surface to form carburizing layer under cathode and anode ionization.The formation of oxide film and hydrogen embrittlement can be avoided under the vacuum treatment conditions.The plasma carburizing layer is deep,TiC concentration is higher,and the carburizing period is short.In this paper,the similarities and differences of three different carburizing processes of titanium alloys are compared,and the research prospects of carburizing treatment of titanium alloys are proposed.

关 键 词：钛 钛合金 渗碳 机理 组织形貌 

分 类 号：TG146.23[一般工业技术—材料科学与工程]