氩弧熔覆Ti-BN涂层的微观组织及耐磨性

Microstructure and wear resistance of Ti-BN coating by argon arc cladding

为提高低碳钢表面的耐磨性能,以钛粉、氮化硼粉和Ni60A粉为原料,利用氩弧熔覆技术在Q235钢基体表面原位合成了TiN-TiB_2增强镍基复合涂层。利用X射线衍射仪、扫描电子显微镜和透射电子显微分析复合涂层的物相和显微组织结构;利用显微维氏硬度计和摩擦磨损试验机测试复合涂层的显微硬度和耐磨性能。结果表明:复合涂层主要由Cr_(23)C_6、γ-Ni、TiN、TiB_2等物相组成,与基体结合良好;复合涂层主要由白色颗粒状TiN和黑色棒状TiB_2组织组成;复合涂层中强化相的生成显著提高了基体硬度,复合涂层平均硬度可达13.5 GPa,较Q235钢基体提高近9倍;复合涂层具有较低的摩擦系数和优异的室温干滑动摩擦磨损性能。

This paper introduces the effort to improve the wear resistance of low-carbon steels.The research involves in situ synthesizing the TiN-TiB2 particles reinforced Ni-based composites coating on the Q235 steel surface by argon arc cladding of mixed titanium powder, boron nitride powder and Ni60A powder;analyzing the microstructure and phase of the composite coating using X-ray diffraction, scanning electron microscopy, and transmission electron microscop;and examining microhardness and wear resistance of the composite coating by means of micro-hardness tester and wear tester.The results demonstrate that the composite coating exhibits a better combination with substrates and consists mainly of the phases： Cr23C6,γ-Ni,TiN and TiB2;the composite coating is composed mainly of white granular TiN and black rod TiB2;the formation of strengthening phase in composite coatings gives a significantly improved substrate hardness;and the composite coating boasts an average micro-hardness of up to 13.5 GPa, about nine times that of Q235 steel matrix.The composite coating demonstrates a lower friction coefficient and an excellent antifriction property.