Effect of alloy elements on microstructures and properties of Fe-based matrixes for diamond segment

Fe-based matrixes for diamond segments were produced by Fe, Cu, Sn, and Ni powders. The mixture experiment was designed to predict the effect of element content on the matrixes performance. In the results, the matrix consists of α-Fe phase, γ(Fe, Ni) phase, Cu_13.7Sn solid solution, and the brittle phase of Cu₃Sn compounds. With the increase of Sn mass fraction, the content of Cu_13.7Sn solid solution by mass decreases, and the content of Cu₃Sn brittle phase by mass increases. When the Sn mass fraction increases to a certain extent, all the Cu_13.7Sn solid solution in microstructures is transformed into Cu₃Sn brittle phase, resulting that the matrix hardnes increases first and then tends to be stable. The higher the Sn mass fraction is, the more brittle phases in the matrix are, which will separate the matrix and lower the bending strength. Ni has the effect of solution strengthening in Cu and Fe, therefore the hardness and bending strength of the matrix are improved with the increase of Ni content by mass. At the lower Sn content by mass, the content of Cu_13.7Sn solid solution by mass increases with the increase of Cu content, resulting in the lower hardness of the matrix. At the higher Sn content by mass, the content of Cu₃Sn brittle phase by mass increases with the increase of Cu content, resulting in the higher hardness. Cu has the effect of solution strengthening in Ni and Fe, thus improving the bending strength of the matrix.