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激光熔覆镍基复合涂层在改善H13模具钢表面性能方面具有显著优势。在H13钢表面激光熔覆WC质量分数分别为20%、33%、50%的WC/Ni60A复合粉末,在优化工艺参数的基础上研究熔覆层的微观组织。研究发现,激光熔覆WC/Ni60A复合涂层的相组成复杂。WC的含量会显著影响熔覆层组织的生成及其形态。WC质量分数为20%时,熔覆层由大量γ-(Fe,Ni)树枝晶和晶间富W碳化物组成;WC质量分数为33%时,熔覆层由大量的团絮状共晶组织组成,其中心为块状M_(23)C_6,周围为M_(23)C_6和γ-(Fe,Ni)组成的共晶组织,形态非常特殊;WC质量分数为50%时,熔覆层中生成了大量块状M6C、雪花状M23C6和针状Cr4Ni15W组织。WC质量分数分别为20%、33%、50%时,熔覆层的硬度相对于基体显著提高,分别达到了730、760、810 HV。
Laser cladding nickel-based composite coatings have significant advantages in improving the surface properties of H13 die steel. The WC / Ni60A composite powders with WC content of 20%, 33% and 50% were laser cladding on the surface of H13 steel. The microstructure of the cladding layer was studied on the basis of optimizing the process parameters. The study found that laser cladding WC / Ni60A composite coating phase composition is complicated. WC content will significantly affect the formation of cladding layer and its morphology. When the mass fraction of WC is 20%, the cladding layer consists of a large amount of γ- (Fe, Ni) dendrites and intergranular W-rich carbides. When WC content is 33%, a large amount of flocculent eutectic (23) C_6, surrounded by M_ (23) C_6 and γ- (Fe, Ni), the morphology is very special. When the mass fraction of WC is 50%, the cladding layer In a large number of massive M6C generated, snow-like M23C6 and acicular Cr4Ni15W organizations. When the mass fraction of WC is 20%, 33%, 50% respectively, the hardness of the coating increases significantly with respect to the matrix, reaching 730, 760 and 810 HV respectively.