首页|ZrC增强激光熔覆CoCrNi合金熔覆层的组织及性能

ZrC增强激光熔覆CoCrNi合金熔覆层的组织及性能

扫码查看
采用激光熔覆技术,在低碳钢表面制备了 ZrC增强的CoCrNi合金涂层.研究了不同ZrC含量(0%,1%,3%,5%,质量分数)对CoCrNi基中熵合金涂层组织、硬度和耐磨性的影响.利用XRD、SEM和EDS分析了涂层的相组成及微观组织结构,并采用显微硬度和摩擦磨损试验对样品的硬度和耐磨性进行测试.结果表明:熔覆层与基体形成了良好的冶金结合,没有出现明显的裂纹及空洞等缺陷.不含ZrC的CoCrNi中熵合金涂层由单相fcc结构组成,随着涂层中ZrC的加入,涂层中的物相组成变为了 fcc+ZrC0.7+Cr23C6+ZrO2.涂层的晶粒得到了明显细化,实现了晶界强化、固溶强化和弥散强化(Orowan)的共同作用,形成的碳化物Cr23C6相与fcc固溶体结合形成共晶碳化物,起到了协同强化作用,有效地提高了涂层的硬度和耐磨性.ZrC中的Zr与空气中的杂质O结合生成的ZrO2也对涂层的性能产生了不利影响,主要是因为ZrO2的存在会导致涂层中颗粒分布不均匀加剧,弱化弥散强化的作用.当ZrC较少时,涂层的性能并未得到较好的提升;当涂层中ZrC含量增加到5%(质量分数)时,涂层中析出了较多的强化相ZrCo.7能够有效的提高材料的性能,该涂层的最大硬度(HVo.i)为(6379.8±147)MPa,摩擦系数为0.161,相较于不含ZrC的涂层均有较大的提升.
Microstructure and Properties of ZrC Enhanced Laser Cladding CoCrNi Alloy Cladding Layer
ZrC enhanced CoCrNi-based laser cladded coatings with different ZrC contents were prepared on the surface of low carbon steel.The effects of ZrC addition on microstructure,hardness and wear resistance of CoCrNi-based medium entropy alloy coating were investigated.The results show that there is a good metallurgical bond between the cladding layer and the matrix without obvious cracks and defects.The CoCrNi alloy coating without ZrC is composed of single-phase fcc structure.With the addition of ZrC into the coating,phase compositions of the coating change to fcc+ZrCo.7+Cr23C6+ZrO2 multiple phase structures.The grains of the coating are significantly refined,and the combination of grain boundary strengthening,solution strengthening and dispersion strengthening(Orowan)is realized,which effectively improve the hardness and wear resistance of the coating.However,ZrO2 produced by the combination of Zr in ZrC and O in the air also has an adverse effect on the performance of the coating,mainly because the presence of ZrO2 will cause the uneven distribution of particles in the coating and weaken the effect of dispersion strengthening.Therefore,when the content of ZrC is low,the performance of the coating is not improved.However,when ZrC content in the coating increases to 5wt%,more ZrCo.7 phase is separated out from the coating,which can effectively improve the performance of the material.The hardness(HVo.1)is(6379.8±147)MPa and the coefficient of friction is 0.161,which is much lower owing to the synergetic strengthening effect.

ZrClaser claddingCoCrNimicrostructurewear resistance

刘冉、党鲜婷、陈楚琦、吴韬

展开 >

北方工业大学机械与材料工程学院,北京 100144

浙江机电职业技术学院,浙江杭州 310053

ZrC 激光熔覆 CoCrNi合金 微观结构 性能

国家自然科学基金

51074204

2024

稀有金属材料与工程
中国有色金属学会,中国材料研究学会,西北有色金属研究院

稀有金属材料与工程

CSTPCD北大核心
影响因子:0.634
ISSN:1002-185X
年,卷(期):2024.53(3)
  • 37