| 引用本文: | 周芳, 朱涛, 何良华.激光熔覆原位合成TiC-TiB2复合涂层[J].中国表面工程,2013,26(6):29~34 |
| ZHOU Fang, ZHU Tao, HE Lianghua.In-situ Synthesized TiC-TiB2 Composite Coatings Prepared by Laser Cladding[J].China Surface Engineering,2013,26(6):29~34 |
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| 摘要: |
| 为了提高材料表面的强度及耐磨性，在Fe901自熔性合金粉末中添加了不同比例的（TiO2+B4C+C+Al）混合粉末，采用激光熔覆技术在45钢表面成功制备了TiC-TiB2增强复合涂层。利用X射线衍射仪(XRD)、扫描电镜(SEM) 、显微硬度计和磨损试验机等对复合涂层的相组成、显微组织形貌及力学性能进行了分析，同时对反应体系进行了热力学计算。结果表明：复合涂层与基材呈冶金结合，无气孔、裂纹等缺陷。反应体系满足原位合成TiC和TiB2的热力学条件。涂层物相由αFe、TiC、TiB2和 (Fe,Cr)7C3组成。细小的方块状TiC颗粒和长条状TiB2均匀弥散分布于涂层基体上，可起到进一步细化组织及沉淀强化的作用。添加（TiO2+B4C+C+Al）混合粉末后，涂层组织明显细化且树枝晶数量减少，并且随着添加量增多，组织越细小。TiCTiB2增强复合涂层显微硬度在720~760 HV0.2之间，比不含TiC-TiB2的涂层提高了30%左右，耐磨性明显提高，混合粉末添加质量分数为50%时耐磨性最好。 |
| 关键词: 激光熔覆 复合涂层 显微组织 力学性能 |
| DOI：10.3969/j.issn.1007-9289.2013.06.005 |
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| In-situ Synthesized TiC-TiB2 Composite Coatings Prepared by Laser Cladding |
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ZHOU Fang, ZHU Tao, HE Lianghua
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School of Materials and Metallurgy, Guizhou University, Guiyang 550025
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| Abstract: |
| To increase the strength and wear resistance of material surface, adding mixedpowder with different mass fraction into Fe901 selffluxing alloy powder, the composite coatings reinforced by TiC-TiB2 were successfully prepared on 45 steel surfaces by laser cladding. The mixedpowder was the mixture of TiO2, B4C, C and Al. The phases, microstructure and mechanical properties were analyzed by Xray diffraction (XRD), scan electron microscopy (SEM), microhardness tester and wear tester. The thermodynamics of each reaction in the system was calculated. The results show that, the interfaces of composite coatings and their substrate material are metallurgically bonded, and the coatings are uniform and dense without cracks and pores. Insitu synthesizing, the phases of TiC and TiB2 are thermodynamically possible. The composite coatings are composed of αFe, TiC, TiB2 and (Fe,Cr)7C3. The fine blockshaped TiC particles and stripshaped TiB2 uniformly disperse in the matrix of coatings. They can fine the microstructure further and play the role of precipitationstrength. The size of microstructure and the amount of dendrite decrease markedly after adding the mixedpowder. The more the mixedpowder is, the finer the microstructure becomes. The average microhardness values of the coatings reinforced by TiC-TiB2 are between 720 HV0.2 and 760 HV0.2, which are 30% higher than that of the coating without TiCTiB2, and their abrasion resistances increase obviously. The lowest mass loss can be obtained when the mass fraction of mixedpowder is 50%. |
| Key words: laser cladding composite coatings microstructure mechanical properties |
