Friction sintering of brass powder

Abstract

ABSTRACT Electrolytic brass powder with nano-sized features was sintered using a newly developed friction sintering process. The brass powder was initially pressed with a 5-ton load for 1 min at room temperature, in a hydraulic press, to convert it into a green pellet. Green pellets were of 16 mm diameter and 14 mm height. The developed friction sintering process is energy efficient, quick, economical, green, and easy to use. The process also ensures easy release of sintered parts. Here, green pellets were initially placed in 14 mm thick aluminum plates with 16 mm diameter through holes. . Applied axial load, tool rpm, and tool diameter decide the rate of heating. In this work, sintering was done using WC tool with12 kN axial load, 800 rpm tool rotational speed, and 18 mmtool diameter. Axial load and tool rpm were kept constant through the process. Pellet temperatures were measured at two different depths using K-type thermocouples. Observed heating rates were much higher than that in spark plasma sintering or hot pressing. SEM (scanning electron microscope) images of fractured surfaces for sintered pellets show neck formation between brass particles. However, the neck formation is different at different depths.