Based on the background of automotive mold surface strengthening, the effects of three different enhancements on the microstructure evolution, micro-hardness and wear resistance of laser cladding cobalt-based coatings were studied. The three reinforcing materials were Co45 alloy powder, Co45/8% B4C mixed powder and Co45/8% B4C/5% Cr3C2 mixed powder. They were respectively used to conduct laser cladding on the surface of die steel with preset powder method, with laser power of 2000[Formula: see text]W and scanning speed of 4[Formula: see text]mm/s. According to the test results, the hardness and wear resistance of the cladding coating were the best when Co45/8% B4C powder was added. In addition, the study also found that B4C reacted with Cr3C2 during laser cladding to eventually generate Cr2B. The CrB2 generated for the first time during the reaction was transformed into the most stable Cr2B with an orthorhombic Fddd symmetry due to its poor stability. Therefore, the sample with Co45/8% B4C/5% Cr3C2 mixed powder was affected with a slight decrease in microhardness and wear resistance.

中文翻译：

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B4C和CR3C2对激光熔覆钴基合金涂层组织和性能的影响

以汽车模具表面强化为背景，研究了三种不同强化对激光熔覆钴基涂层组织演变、显微硬度和耐磨性的影响。三种增强材料分别为Co45合金粉、Co45/8%B4C混合粉和Co45/8% B4C/5% 铬3C2混合粉末。分别采用预设粉末法对模具钢表面进行激光熔覆，激光功率为2000[公式：见正文]W，扫描速度为4[公式：见正文]mm/s。试验结果表明，Co45/8% B时熔覆层的硬度和耐磨性最好。4加入C粉。此外，研究还发现，B4C与Cr反应3C2在激光熔覆过程中最终生成 Cr2B. CrB2反应过程中第一次产生的转化为最稳定的Cr2由于稳定性差，B 具有正交 Fddd 对称性。因此，含有 Co45/8% B 的样品4C/5% 铬3C2混合粉末的显微硬度和耐磨性略有下降。