摘要
用同轴送粉的方式在42CrMo表面激光熔覆Fe-WC合金粉末,通过扫描电镜、光学显微镜、能谱仪观察分析熔覆层的显微组织特征、WC陶瓷颗粒对熔覆层组织性能的影响、WC陶瓷颗粒分布特征及WC周围块状共晶物的组成成分;用显微硬度计、摩擦磨损试验仪、高精度电子天平测量基体与熔覆层的性能及质量损失,分析了引起性能曲线变化的原因。结果表明,熔覆层底部到顶部的组织变化为平面晶、晶界明显的胞状晶、交错生长的柱状树枝晶、排列紧密的胞状晶、方向均一的柱状树枝晶;WC陶瓷颗粒具有细化枝晶、阻断枝晶生长,增强熔覆层性能的能力;WC陶瓷颗粒在熔覆层中聚集分布,形成较宽的陶瓷带;WC陶瓷颗粒周围的块状共晶物是由WC部分分解得到的,其组成元素包括C、W、Fe、P、Cr。熔覆层平均硬度达到850 HV0.3,是基体平均硬度的3.4倍。摩擦因数为0.275左右,比基体小0.525。基体的质量损失是熔覆层的11倍多。说明Fe-WC合金熔覆层能够有效提升基体的硬度及其抗磨损能力。
Fe-WC alloy powder was laser cladded on the surface of 42CrMo steel by coaxial powder feeding method.The microstructure characteristics of the clad layer,the influence of WC ceramic particles on the microstructure and properties of the clad layer,the distribution characteristics of WC particles and the composition of bulk eutectic around WC particles were observed and analyzed by scanning electron microscope,metallographic microscope and energy spectrometer.The performance and mass loss of the matrix and the clad layer were measured by microhardness tester,friction and wear tester,and high precision electronic balance,and the reasons causing the change of performance curves were analyzed.The results show that the microstructure changes from the bottom to the top of the clad layer are planar grains,cellular grains with obvious grain boundary,columnar dendrite with staggered growth,closely arranged cellular grains and columnar dendrite with uniform direction.The WC particles have the ability to refine dendrites,to block dendrite growth and to enhance the clad layer performance.The WC particles are aggregated and distributed in the clad layer to form a wider ceramic belt,and the massive eutectic around the WC particles is obtained by partial decomposition of WC,and the constituent elements of the eutectic include C,W,Fe,P and Cr.The average hardness of the clad layer reaches 850 HV0.3,which is 3.4 times of that of the matrix.The friction factor is about 0.275,which is 0.525 smaller than that of the matrix.The mass loss of the matrix is more than 11 times that of the clad layer.This shows that the Fe-WC alloy clad layer can effectively improve the hardness and wear resistance of the matrix material.
作者
崔陆军
于计划
曹衍龙
曾文涵
郭士锐
李晓磊
Cui Lujun;Yu Jihua;Cao Yanlong;Zeng Wenhan;Guo Shirui;Li Xiaolei(School of Mechatronics Engineering,Zhongyuan University of Technology,Zhengzhou Henan 450007,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第10期199-203,共5页
Heat Treatment of Metals
基金
河南省高等学校重点科研项目(20A460033,19A460035,20A460031)
中国纺织工业联合会科技指导性项目(2016085)
中原工学院自主创新应用研究项目(K2018YY001)。
