The effect of pressure and temperature on the properties of 88 W-10Ni-2Mn tungsten heavy alloy produced by cold press method

Abstract

This research explored the impact of pressure and temperature to determine the optimal conditions for producing an 88 W-10Ni-2Mn tungsten heavy alloy (WHA) suitable for industrial purposes. To achieve this objective, tungsten, nickel, and manganese powders with predetermined ratios underwent wet milling in a two-step process. Subsequently, the powder mixture underwent compression at two pressures, namely 200 MPa and 250 MPa, employing the cold press method. The compressed mixture was then subjected to sintering in a tubular furnace at temperatures of 1200 °C, 1250 °C, 1350 °C, and 1400 °C. Microstructural characterization was conducted using optical and scanning electron microscopes (SEM). The findings indicated that increasing both pressure and temperature resulted in an enhancement of the sintering density in the samples. The optimum value was achieved at 1400 °C and 250 MPa, reaching 90.11 g/cm3. Furthermore, in the quenching sintering process, the carburization of 88 W-10Ni-2Mn WHA contributed to an increase in the micro hardness of the samples, reaching a maximum of 529 HV. The hardness exhibited an increase from 355 HV to 529 HV with a temperature rise from 1200 °C to 1250 °C. However, it decreased from 377 HV to 352 HV when the temperature increased from 1350 °C to 1400 °C. The increase of sintering temperature also led to slightly increases the continuity of tungsten‑tungsten due to the growth of tungsten particles. By increasing the temperature from 1350 °C to 1400 °C, ductile fracture was observed in WHA.