Powder Metallurgy Analisa Pengaruh Variasi Temperatur Warm Compaction Paduan (CuNi)- 5%wt W terhadap Struktur Mikro, Sifat Mekanis dan Konduktivitas Listrik

Abstract

Copper is a material commonly used as the main electrode material for EDM machines. This element is known to have excellent electrical conductivity, but overall it lacks mechanical properties. Generally, improvements in mechanical properties are achieved by increasing the sintering pressure or temperature, by hot compaction during the compaction process, or by combining with other elements to improve the required properties. The optimum temperature for the hot compaction process is generally in the range of 100–200 °C. The aim of this research is to determine the effects of variations in hot compaction temperatures of 100 °C, 200 °C, and 250°C, which are expected to improve the mechanical properties of Cu-Ni-W alloy as an EDM electrode alloy material. For the powder mixing process, a horizontal ball mill is used with a rotation speed of 300 rpm for 2 hours, then it is put into a mold for a compaction process at a pressure of 250 MPa for 15 minutes with a compaction temperature of 100oC, 200oC and 250oC. The sintering process was carried out at a temperature of 770oC in an electric muffle furnace for 60 minutes. The tests include density, hardness, compression, electrical conductivity and microstructure tests. The highest value was achieved at a temperature of 250oC, namely a density of 7.623 g/cm3, a hardness of 100.2 VHN and an electrical conductivity of 60.87% IACS, and the microstructure test results showed that increasing the compaction temperature would result in further bonding of the alloy structure, but more porosity was found.