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采用真空实型铸渗(V-EPC)工艺制备碳化钨颗粒增强钢基表层复合材料,并测试其热膨胀系数和热导率,研究了工艺参数对热物理特性的影响。结果表明,随着测试位置与表层复合材料过渡区间距的增大热膨胀系数逐渐减小,而在相同位置同一温度下表层复合材料的热膨胀系数随着碳化钨颗粒的增大而增大。不同粒度碳化钨颗粒增强表层复合材料的热导率,均随着温度的升高呈增大趋势。当温度较低(40℃与105℃)时,不同碳化钨颗粒粒度的复合材料的热导率相差不大。但是当温度升高到一定值(大于170℃)时,复合材料的热导率随着碳化钨颗粒粒度的增大呈降低趋势。在预制层中加入Ni粉,可降低表层复合材料的热膨胀系数和热导率。
The vacuum solid infiltration (V-EPC) process was used to prepare tungsten carbide particle reinforced steel-based surface composites. The thermal expansion coefficient and thermal conductivity of the composites were tested. The influence of process parameters on thermal properties was also studied. The results show that with the increase of the distance between the test site and the transition zone of the surface composite, the thermal expansion coefficient decreases gradually. However, the thermal expansion coefficient of the composite increases with the increase of the tungsten carbide particles at the same temperature and the same temperature. The thermal conductivity of the composite with different particle size tungsten carbide particles increases with the increase of temperature. At lower temperatures (40 ° C and 105 ° C), the thermal conductivities of composites with different particle sizes of tungsten carbide differ slightly. However, when the temperature rises to a certain value (greater than 170 ℃), the thermal conductivity of the composites tends to decrease with the increase of the particle size of the tungsten carbide particles. Addition of Ni powder in the prefabricated layer can reduce the thermal expansion coefficient and thermal conductivity of the surface layer composite.