原位生成纳米晶对冷焊熔涂层组织与耐磨性能的影响

Effect of Nanocrystalline In-situ on Microstructure and Wear Resistance of Cold Welding Cladding Layer

为解决异形面涂层在高频感应熔覆或真空炉熔覆中存在的熔体下坠、厚薄不均匀等问题,采用冷焊技术在45钢表面熔涂Ni60镍基合金。试验中,利用多种理化手段分析了熔涂层的微观组织和成分;利用显微维氏硬度仪和往复式摩擦磨损试验机分别测试了熔涂层的显微硬度和磨损性能。结果表明:熔涂层与基体形成了良好的冶金结合,且熔涂层内含有部分非晶态合金;热处理后,熔涂层内非晶态合金原位形成纳米晶,使熔涂层二次强化;熔涂层的最终HV硬度可达745~983,耐磨性提高。

In order to solve the problems such as the melting falling and uneven thickness which existed in special-shaped cladding layer by high-frequency induction melting or in vacuum furnace,the Ni60 Ni-based alloy was deposited to 45 steel surface by cold welding technique.In the experiment,the microstructure and composition of the cladding layer were analyzed by various physical and chemical methods.The micro-hardness and wear properties of the cladding layer were tested by using micro-Vickers hardness tester and reciprocating friction wear testing machine respectively.The results show that the cladding layer and substrate forms a good metallurgical bond,and the cladding layer contains some amorphous alloy.After heat treatment,the amorphous alloy in the cladding layer is formed situ-nano crystallines,therefore which maked secondary strengthening of cladding layer.The final HV hardness of cladding layer is up to 745-983,and the wear resistance is improved.