Si 含量对 FeCoCr0. 5 NiBSix 高熵合金涂层组织结构和耐磨性的影响

目的研究Si含量对激光熔覆FeCoCr_(0.5)NiBSi_x高熵合金涂层组织结构、硬度和耐磨性的影响。方法采用激光熔覆技术,在45钢基体表面制备了不同Si含量的FeCoCr_(0.5)NiBSi_x(x取0,0.1,0.2,0.3,0.4)系列高熵合金涂层,分析涂层的宏观形貌、微观组织及相结构,测试涂层的硬度,通过摩擦磨损实验测试涂层的耐磨性。结果熔覆态高熵合金涂层均由FCC相和M2B相组成,显微组织包括先共晶组织和共晶组织。随着Si含量的增加,FCC相增多,M_2B相减少,共晶组织由蜂窝状到颗粒状,然后消失。高熵合金涂层的平均硬度随着Si含量的增加而先降低后增加,FeCoCr_(0.5)NiBSi0.3的硬度值最小(613HV),FeCoCr_(0.5)NiBSi_(0.4)的硬度值最高(820HV)。高熵合金涂层的磨损体积随着Si含量的增加而先增大后减小,FeCoCr_(0.5)NiBSi_(0.3)的磨损体积最大(0.00406mm3),FeCoCr_(0.5)NiBSi0.4的磨损体积最小(0.00233mm3)。结论随着Si含量增加,涂层的M2B相减少,共晶组织逐步消失,耐磨性则先降低后提高。耐磨性能最好的是FeCoCr_(0.5)NiBSi_(0.4)高熵合金涂层。

Effect of Silicon Content on the Microstructure and Wear Resistance of FeCoCr0. 5NiBSix High-entropy Alloy Coatings

Objective To study the effect of silicon content on the micro-structure, hardness and wear resistance of FeCoCr0.5NiBSix high-entropy alloy coatings. Methods FeCoCr0. 5NiBSix high-entropy alloy coatings were prepared on 45 steel substrate by laser cladding. The macro-morphology, microstructure and phase structure of the coating were analyzed, the hardness of the coating was tested and the wear resistance of the coating was tested using the friction wear experiment. Results The as-cladding alloys were composed of FCC phase and M2 B phase, and the microstructures of the coatings were composed of pro-eutectic microstructure and eutectic microstructure. With the increase of silicon content, the volume fraction of FCC phase increased, while that of M2 B phase decreased, the shape of eutectic changed from cellular to granulate and then disappeared. The average hardness of the coating first decreased and then increased with the increasing silicon content. The FeCoCr0. 5 NiBSi0. 3 coating had the minimal hardness, which was 613HV, whereas the FeCoCr0. 5 NiBSi0. 4 coating had the maximal hardness, which was 820HV. The wear volume first increased and then decreased with the increasing silicon content. The wear volume of FeCoCr0. 5 NiBSi0. 3 coating was the maximum, which was 0. 004 06 mm3 , whereas the friction volume of FeCoCr0. 5 NiBSi0. 4 coating was the minimum, which was 0. 002 33 mm3 . Conclusion With the increase of silicon content, the volume fraction of M2 B phase decreased, and the eutectic microstructure disappeared gradually, the wear resistance of coating first increased and then decreased. The abrasive resistance of the FeCoCr0. 5 NiBSi0. 4 high-entropy alloy coating was the best.