FEATURES OF THE SINTERING OF FE–CU–SN–NI AND CU–TI–SN–NI POWDERS  DURING HOT PRESSING 

Abstract

The efficiency and durability of a diamond tool fabricated using powder metallurgy methods depend on several factors. These are the quality of diamond materials, composition of a bond and its physicomechanical and physicochemical properties, as well as the nature and structure of the initial metal powders for sintering of a diamond-composite material, i.e., a functional element of a diamond tool. This paper examines the dispersion influence of the initial metal powders on the hot-pressing sintering process in two metal systems, Fe–Cu–Sn–Ni and Cu–Ti–Sn–Ni. In the first case, the initial charge was a mixture of independent Fe, Cu, Sn, and Ni metal powders. In the second case, we used the powder of the Cu–Ti–Sn–Ni alloy, previously melted and dispersed in ball mills. The effect of dispersion, size distribution, morphology, average mass diameter on the density, and hardness of sintered metal samples was then studied. It was revealed that the sintering capacity and features of the sinters are directly dependent on the dispersion of the initial powders for the Fe–Cu–Sn–Ni system. In contrast, the initial charge is a classical mixture of individual metallic powders. When using powders of Cu–Ti–Sn–Ni alloys, the revealed dependence of the dispersion of the initial powder in the alloy on sinterability and properties of the sinters is no longer observed. During the experiment, reverse phenomena were established. Thus, the best results were achieved when using a coarse grain size of the alloy powder. In this work, we showed the possibility of producing pre-melted alloy powder of a planned composition based on copper (Cu ≥ 77%) Cu–Ti–Sn–Ni with a Ti content >10% by mechanical activation for the further successful implementation as a binder of diamond tools.