前驱体碳化复合等离子熔覆涂层  

Plasma cladding coatings by precursor carbonization-composition process

作　　者：刘均波[1] 黄继华[2] 刘均海[2,3] 宋桂香[4] 

机构地区：[1]潍坊学院机电工程系,潍坊261041 [2]北京科技大学材料科学与工程学院,北京100083 [3]威海职业学院机电工程系,威海264210 [4]威海职业学院职业技能实训中心,威海264210

出　　处：《北京科技大学学报》2011年第5期581-586,共6页Journal of University of Science and Technology Beijing

基　　金：山东省科技攻关项目(No.2007GG30003003)

摘　　要：以钛铁粉、铬粉、铁粉和碳的前驱体(蔗糖)等为原料,通过前驱体碳化复合技术制备了碳化复合粉,并利用等离子熔覆技术在Q235钢表面制备了Fe-Cr-C和Fe-Cr-C-Ti涂层.采用X射线衍射和扫描电镜对涂层的相组成和显微组织结构进行了分析.结果表明:Fe-Cr-C涂层由(Cr,Fe)_7C_3初生碳化物和菊花瓣状分布共晶碳化物(Cr,Fe)_7C_3与奥氏体组织组成;Fe-Cr-C-Ti涂层由原位合成的TiC相和(Cr,Fe)_7C_3共晶相与奥氏体相构成.这两种涂层与基体之间都是冶金结合.涂层中碳化物TiC的体积分数呈现梯度分布,并且涂层的熔合区和中部区域TiC颗粒形状多为等轴状颗粒,涂层的表层区域部分TiC颗粒多为树枝晶颗粒.与Fe-Cr-C涂层相比较,Fe-Cr-C-Ti涂层的抗开裂性更好.Fe-Cr-C和Fe-Cr-C-Ti两涂层的平均显微硬度约是750HV_(0.2),是基体金属的3.2倍,从涂层表面到熔合区相差不大.A process of preparing Fe-Cr-C composite powder for precursor carbonization-composition process was developed using the compacts of mixed ferrotitanium, chromium, iron and carbon precursor （saccharose） powers as raw materials, and Fe-Cr-C and Fe-Cr-C-Ti composite coatings were synthesized and deposited on Q235 steel substrates by plasma cladding technology. The phase composition and microstructure of the composite coatings were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. It is shown that the Fe-Cr-C composite coating consists of （Cr,Fe）_7C_3 primary phase, （Cr,Fe）_7C_3 eutectics with a petal-like distribution and austenite, but the Fe-Cr-C-Ti composite coating is composed of in situ TiC and （Cr,Fe）_7C_3 eutectics and austenite. The two types of composite coatings are also metallurgically bonded to the substrates. The volume content of TiC in the coating shows a gradient distribution. Generally, TiC phases in the fusion zone and central regions are equiaxed, and TiC phase in the surface is dendritic. Compared with the Fe-Cr-C composite coating, the Fe-Cr-C-Ti composite coating has better anti-cracking. The average microhardnesses of the Fe-Cr-C and Fe-Cr-C-Ti composite coatings are about 750 HV_（0.2）, 3.2 times as large as the microhardness of the based metal, and this value changes little from the surface to the fusion zone.

关 键 词：涂层 等离子熔覆 碳化钛 前驱体 原位合成 

分 类 号：TG174.4[金属学及工艺—金属表面处理]