Abstract Copper matrix composites reinforced with graphite flakes (GFs/Cu) were fabricated by powder hot pressing method and the alloying chromium (Cr) element in powdered form was directly added into the Cu matrix powder to enhance the interfacial bonding between GFs and Cu matrix. Effects of addition of Cr on thermal conductivity (TC), coefficient of thermal expansion (CTE), and bending strength of GFs/Cu composites in X Y (basal plane of GF) and Z directions were investigated in this study. The results showed that in X Y direction, the TC of 50 vol% GFs/Cu composites increased from 560 to 628 W m−1 K−1 after adding 2.0 wt% Cr, and the bending strength nearly doubled from 53.8 (GF/Cu) to 93 MPa. The CTE in Z direction could be obviously reduced with Cr addition, which dropped gradually from 9.4 to 3.2 ppm K−1 at 150 °C with the increase in content of Cr from 0 to 5.0 wt%. This improvement in TC, bending strength, and CTE is attributed to the formation of carbide transition layer at the interface between Cu and graphite. The detailed influence of carbide layer on the properties of the composites was thoroughly studied by corresponding evolution of interfacial microstructure with increasing Cr content.

中文翻译：

---

基体合金元素铬对热压烧结石墨片/铜复合材料组织和性能的影响

摘要 采用粉末热压法制备石墨片增强铜基复合材料（GFs/Cu），将粉末状合金化铬（Cr）元素直接添加到Cu基体粉末中，以增强GFs与Cu基体的界面结合。本研究研究了添加 Cr 对 GFs/Cu 复合材料在 XY（GF 基面）和 Z 方向的热导率 (TC)、热膨胀系数 (CTE) 和弯曲强度的影响。结果表明，在XY方向上，添加2.0 wt% Cr后，50 vol% GFs/Cu复合材料的TC从560增加到628 W m-1 K-1，弯曲强度从53.8 (GF/Cu)增加近一倍到 93 兆帕。Z方向的CTE随Cr的加入而明显降低，从9.4逐渐下降到3。2 ppm K-1 在 150 °C 下随着 Cr 含量从 0 增加到 5.0 wt%。TC、弯曲强度和 CTE 的这种改进归因于在 Cu 和石墨之间的界面处形成了碳化物过渡层。通过随着Cr含量的增加界面微观结构的相应演变，深入研究了碳化物层对复合材料性能的详细影响。