Effects of different kinds of phosphorus-containing pre-alloyed powder on the microstructures and properties of Fe-based sintered matrix

In this paper, we took the pre-alloyed powder CuP8 and FeP24 as the object, by using SEM, EDS and analyzing the hardness and bending strength of the matrix, to explore how different kinds of phosphorus-containing pre-alloyed powder influence the microstructure and properties of Fe-based sintered matrix. The results have shown that both of the two kinds of matrix are mainly composed of α-Fe, Cu-based solid solution and Fe₃C. However, matrix that has been added FeP24 also contains Fe₂P and FeP. Compared with matrix which contains FeP24, almost all the phosphorus in matrix which contains CuP8 is transferred from CuP8 to α-Fe and more evenly distributed, leading to a higher hardness and bending strength of the matrix. During the hot-pressing process, microcrack would appear on the FeP24 particle and may become the crack source of matrix, reducing the bending strength of the matrix. We thus came to the conclusion that CuP8 can improve the performance of Fe-based diamond tool.