Graphite, whose presence is harmful to the mechanical property, is one of the main reaction products between Ni-based alloy and SiC. This paper reports a method of eliminating graphite based on thermodynamic calculations. Different amounts of Si powders are added into the Inconel 625 powder filler to adjust the interfacial reactions during the brazing process. When the Si content in the liquid reaches the theoretically calculated value, the reactions between the Inconel 625 filler and SiC substrate are suppressed, and no graphite forms on the interface. The graphite-free SiC joints show good oxidation resistance. The joint's strength maintains at 25.7 MPa while that with graphite drastically drops to 5.5 MPa after 185 h oxidation in air. The reaction products and oxidation process of the SiC joints are also carefully analyzed in this paper.

石墨的存在对力学性能有害，是镍基合金与碳化硅的主要反应产物之一。本文报道了一种基于热力学计算消除石墨的方法。在 Inconel 625 粉末填料中添加不同量的 Si 粉末，以调节钎焊过程中的界面反应。当液体中的Si含量达到理论计算值时，Inconel 625填料与SiC衬底之间的反应受到抑制，界面上不会形成石墨。无石墨碳化硅接头表现出良好的抗氧化性。接头的强度保持在 25.7 MPa，而石墨在空气中氧化 185 小时后急剧下降到 5.5 MPa。本文还仔细分析了 SiC 接头的反应产物和氧化过程。