原位反应法制备Cr_2AlC-Fe基复合材料(英文)

Fabrication of Cr_2AlC-Fe Based Composites by in-situ Reaction Technique

采用原位反应法制备了Cr2AlC-Fe基复合材料,通过热分析、X射线衍射、扫描电子显微镜和三点弯曲实验研究了原位反应的烧结工艺对产物物相、显微结构和性能的影响。结果表明:通过高温原位反应,原料中碳化铝铬发生了分解,所生成的碳铬化合物在Fe晶界形成了网络状陶瓷增强结构,所制备的复合材料在室温下具有较好的强度和韧性。但随着碳化铝铬含量的增加,复合材料的强度与断裂韧性之间呈负相关关系。当原料中碳化铝铬的含量为50%,烧结温度为1300℃,在30MPa压力下保温30min时,复合材料的抗弯强度达1417.05MPa,但断裂韧性只有18MPa m1/2。

A chromium aluminum carbide-iron（Cr2AlC-Fe） based composite was fabricated by an in-situ reaction method. The influences of sintcring process on the phase composition, microstmcturc and properties of the Cr2AlC-Fe composites were analyzed by thcrmogra-vimetric-differential thermal analysis, X-ray diffraction, scanning electron microscopy and three-point bending method. The results show that Cr2AlC can in-situ react with Fe, and breaks down into new phase of chromium carbide. The chromium carbide particles mainly distributed uniformly in the Fe matrix and form a hard continuous skeleton in the grain boundaries. The synthesized composite exhibits high flexuml strength and fracture toughness at room temperature. There are a negative correlation between the flexuml strength and fracture toughness. When the Cr2AlC content is 50% in the starting material, and the green compact sintered at 1300 ℃ under 30MPa for 30 min, the flexural strengths of the Cr2AlC-Fe composites can reach 1417.05 MPa with the fracture toughness only 18 MPa·m1/2.