This paper reports the effect of post-heat treatment (PHT) on laser-deposited WxC + Ni-based composite thin walls. The PHT at 700, 800, and 900 °C was conducted to modify the microstructure and mechanical properties of the composite. The results showed that the as-deposited composite had a weak flexural strength and plasticity due to the brittle nature of the eutectic phase. The eutectic phase consisted of M₇C₃, M₂C, and a small amount of the γ phase. However, after PHT at a certain temperature (e.g., 700 or 800 °C), the eutectic phase gradually disappeared, and carbides, such as M₇C₃ and M₂C, tended to be distributed uniformly in the γ matrix, which improved the flexural strength of the composite. Nevertheless, after the PHT at 900 °C, the flexural strength of the composite displayed a downward trend, which was mainly because of the severe softening of the γ phase. In addition, the plasticity of this composite continuously improved as the eutectic phase disappeared and the γ phase softened. Based on the above results, we proposed a PHT at 800 °C for 1 h as an optimal process for this WxC + Ni-based composite.

本文报道了后热处理 (PHT) 对激光沉积 W x C + Ni 基复合材料薄壁的影响。在 700、800 和 900 °C 下进行 PHT 以改变复合材料的微观结构和机械性能。结果表明，由于共晶相的脆性，沉积的复合材料具有较弱的抗弯强度和塑性。共晶相由M ₇ C ₃、M ₂ C和少量的γ相组成。但在一定温度（如700或800℃）PHT后，共晶相逐渐消失，碳化物如M ₇ C ₃和M ₂C，趋于均匀分布在γ基体中，提高了复合材料的抗弯强度。然而，900 ℃ PHT 后，复合材料的抗弯强度呈下降趋势，这主要是由于 γ 相的严重软化。此外，随着共晶相消失和γ相软化，该复合材料的塑性不断提高。基于上述结果，我们提出了在 800°C 下进行 1 小时的 PHT 作为这种 W x C + Ni 基复合材料的最佳工艺。