半导体激光复合溶胶-凝胶工艺对原位合成TiC强化涂层组织形态的影响  

Influence of Diode Laser Cladding and Sol-Gel Compound Technique on Microstructure of in-situ Synthesis TiC Enhanced Coating

作　　者：唐强强 张群莉[1,2] 王梁[1,2] 姚建华[1,2] 

机构地区：[1]浙江工业大学激光加工技术工程研究中心,浙江杭州310014 [2]浙江省高端激光制造装备协同创新中心,浙江杭州310014

出　　处：《中国激光》2015年第B09期190-196,共7页Chinese Journal of Lasers

基　　金：浙江省自然科学基金青年基金（LQ13E050012）、浙江省公益技术研究工业项目（2013C31012）

摘　　要：TiC强化涂层具有硬度高、耐磨、抗氧化等优良性能，广泛应用于工模具表层。激光熔覆原位反应法是一种具有明显优势的制备TiC强化涂层的方法。而通常所用的机械混粉法混粉均匀较困难，粉末混合不均将直接影响TiC的反应生成。采用溶胶凝胶的方法制备TiO2-石墨（C）均匀混合的粉末，通过半导体激光辐照45#钢基体原位反应制备TiC强化涂层。分别采用X射线衍射仪、扫描电子显微镜、显微硬度仪表征涂层的表面物相、显微结构、显微硬度，研究了激光功率、扫描速率、气流量对强化涂层中TiC的含量以及显微结构的影响。结果表明，强化涂层中TiC强化颗粒呈多边形或不规则形状；在满足能够形成熔覆层且生成TiC的前提下，涂层中TiC颗粒含量随激光作用比能量减小而增大、随气流量增大而增大；当激光作用比能量为250W·s／mm^2、气流量为30L／min时，涂层最高硬度达1151HV0.2。TiC enhanced coating has excellent properties, such as high hardness, wear resistance, oxidation resistance, etc. , and it is widely used on the surface of tools and mold. Laser cladding is an ideal method of preparing TiC enhanced coating, but the usually used mechanical mixing powder method is even more difficult to mix the powder even, which directly affects the generation of TiC particles. A new method of sol-gel is used to prepare even TiO2-graphite mixed powder, and the TiC enhanced coating is made by TiO2-C in-situ synthesis through diode laser irradiation on 45 # steel substrate. The phases on the coating surface, microstructure and hardness of the enhanced layer are tested by X-ray diffraction, scanning electron microscopy, micro-hardness tester, respectively. The influences of laser power, scanning speed, gas flow on TiC distribution and microstructure of enhanced coating are investigated. The results show that the shape of generated TiC particles in enhanced coating is polygonal or irregular. On the premise that the cladding layer can be formed and TiC particles can be generated, the energy density is smaller and the gas flowing speed is bigger, more TiC particles is generated in the coating. The maximum hardness of enhanced coating reaches 1151 HV0.2 when laser processing specific energy is 250 W . s/mm^2 and gas flow rate is 30 L/min.

关 键 词：激光技术 溶胶凝胶 原位反应 TIC 半导体激光 强化涂层 

分 类 号：TN249[电子电信—物理电子学] TB331[一般工业技术—材料科学与工程]