摘要: |
为了提高热锻模寿命,采用激光熔覆的方法在热锻模的近表面层W6Mo5Cr4V2上激光熔覆Ni60–Cr3C2金属陶瓷层。用扫描电镜和XRD对熔覆层显微组织结构进行分析;用维氏硬度计测定覆层的显微硬度;用激光热常数测试仪测定覆层的比热及热导率;用动态热机械分析仪测定热膨胀系数;用高温陶瓷试验系统测定弹性模量。结果表明:涂层与基体为冶金结合,熔覆层硬度在912~1713 HV,Ni60–Cr3C2覆层的热物性参数总体与基体相比基本相当。 |
关键词: 激光熔覆 热锻模 热物性参数 热应力 |
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基金项目:国家自然科学基金(50675165);中央高校基本科研业务费专项资金资助(2010-Ⅱ-025) |
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Thermal Parameters Research of Laser Cladding Ni60–Cr3C2 Cermets on Surface of Hot Forging Dies |
PAN Cheng–gang1, 2, WANG Hua–chang2, WANG Hong–fu2, ZHOU Jia–lin11,2
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1. Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology, Wuhan 430081;2. School of Materials Science and Engineering Wuhan University of Technology, Wuhan 430070
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Abstract: |
In order to improve service life of hot forging dies, Ni60–Cr3C2 composite coatings were prepared on the high speed steel W6Mo5Cr4V2 using laser cladding technology. Microstructure observation and microhardness of laser clad coatings with several ratios of Ni60:Cr3C2 were investigated by scanning electron microscopy (SEM), XRD and microhardness tests, respectively; specific heat and thermal conductivity were measured by Laser Thermal Constant Meter; thermal expansion coefficient and elastic modulus were measured by Dynamic Mechanical Thermal Analyzer and High Temperature Ceramic experimental system, respectively. The results show that the coating with metallurgical bonding is obtained between the cladding layer and the substrate. The microhardness of the surface cladding layer can be up to 912~1713 HV, thermal parameters of Ni60–Cr3C2 coating in general ,compared to the substrate, has no major improvement. |
Key words: laser cladding hot forging die thermal parameters thermal stress |