| 摘要: |
| 为改进 45#钢表面硬度低、耐磨性差的缺点，拓宽其在工业生产中应用范围，选择激光熔覆技术在其表面制备 Ni60(N1)、 Ni60-10%Cu(N2)、Ni60-20%Cu(N3)(wt.%)三种耐磨复合涂层，研究三种涂层的微观组织、显微硬度及摩擦学性能。结果表明： N1 涂层主要包括 γ-Ni 固溶体、Cr7C3 硬质相、FeNi3 金属间化合物，N2、N3 涂层额外含有固体润滑相 Cu。性能上 N1(730.41 HV0.5)、N2(653.04 HV0.5)和 N3(592.29 HV0.5)涂层的显微硬度均高于基体，分别达到基体(299.20HV0.5)的 2.44、2.18 和 1.98 倍；室温下 N3 涂层表现出优异的减摩性能，摩擦因数比 N1 涂层降低 8.5%，N2 涂层表现出优异的耐磨性能，磨损率为 1.74×10?5 mm3 (N·m)，而添加 20%Cu 后，涂层对硬质相的支撑下降，导致硬质相剥离涂层，进而破坏润滑膜，导致磨损率上升。然而在 600 ℃下，N1 涂层的减摩性能最佳，摩擦因数比基体下降 50.7%，N2 涂层耐磨性最高，磨损率为 5.99×10?5 mm3 (N·m)，低于 N3 涂层的磨损率 9.02×10?5 mm3 (N·m)，这是因为添加固体润滑相 Cu 对涂层的保护作用不足以抵消涂层硬度下降的负面影响。为固体润滑相 Cu 改进 Ni60 复合粉末，进而制备成自润滑复合涂层提供了添加量参考范围。 |
| 关键词: 45#钢 激光熔覆 Ni60 / Cu 自润滑复合涂层 固体润滑 |
| DOI：10.11933/j.issn.1007?9289.20220428002 |
| 分类号:TG146;TH117 |
| 基金项目:国家自然科学基金(52075559)、湖南省重点研发计划(2022GK2030)、湖南省自然科学基金(2021JJ31161)、先进金属材料绿色制备与表面技术教育部重点实验室开放基金(GFST2021KF03)和湖南省研究生科研创新(CX20220729)资助项目 |
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| Microstructure Evolution and Tribological Properties of Laser Cladding Ni60 / Cu Self-lubricating Composite Coatings on 45# Steel |
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WANG Quan1, LIU Xiubo1,2, LIU Qingshuai1, WANG Gang1, ZHANG Shiyi1, ZHANG Lin2
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1.Hunan Province Key Laboratory of Materials Surface / Interface Science & Technology,Central South University of Forestry & Technology, Changsha 410004 , China;2.Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials ofMinistry of Education, Anhui University of Technology, Maanshan 243002 , China
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| Abstract: |
| To improve the low surface hardness and poor wear resistance of 45 # steel and broaden its application range in industrial production, three kinds of wear-resistant composite coatings of Ni60, Ni60-10%Cu and Ni60-20%Cu (wt.%) are prepared on the its surface by laser cladding technology. The microstructure, microhardness and tribological properties of the three coatings are investigated. The results show that the N1 coating mainly includes γ-Ni solid solution, Cr7C3 hard phase and FeNi3 intermetallic compound, and the N2 and N3 coatings contain extra solid lubricant Cu. In terms of performance, the microhardness of N1 (730.41 HV0.5 ), N2 (653.04 HV0.5 ) and N3 (592.29 HV0.5 ) coatings is higher than that of the substrate, which is 2.44, 2.18 and 1.98 times higher than that of the substrate ( 299.20 HV0.5 ), respectively. At room temperature, the N3 coating shows excellent friction reduction performance, and the friction coefficient is 8.5 % lower than that of the N1 coating. The N2 coating shows excellent wear resistance, and the wear rate is 1.74×10?5 mm3 (N·m). However, after the addition of 20 % Cu, the support of the coating on the hard phase decreases, resulting in the stripping of the coating on the hard phase, thus damaging the lubricating film and increasing the wear rate. However, at 600 ℃, N1 coating has the best friction reduction performance, and the friction coefficient decreases by 50.7 % compared with the substrate. The wear resistance of N2 coating is the highest, and the wear rate is 5.99×10?5 mm3 (N·m), which is lower than that of N3 coating, 9.02×10?5 mm3 (N·m). This is because the protective effect of solid lubricant Cu on the coating is not enough to offset the negative impact of the decrease of coating hardness. This paper provides reference for the addition of solid lubricating phase Cu to the Ni60 composite powder, and then prepare self-lubricating composite coating. |
| Key words: 45# steel laser cladding Ni60 / Cu self-lubricating composite coating solid lubrication |
