Effect of powder metallurgy preparation process on properties of TiC reinforced high chromium cast iron matrix composites

Abstract

TiC reinforced high chromium cast iron(HCCI) matrix composites were prepared by high energy ball milling and vacuum sintering.Scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were employed to analyze the powder at different time of ball milling.The effect of sintering temperature on microstructures, hardness and densities of high chromium iron-based composites was explored.The wear resistance of the composites and high chromium cast iron under the same process was compared.The results show that the size of powder particles tends to be stable, the powder activity increases and the sintering property is improved after 12 h of ball milling.TiC in sintered samples is uniformly distributed in the matrix.The grains in the composites grow gradually, the hardness and densities of the composites continuously increase with the increase of sintering temperature.After sintering for 2 h under the condition of supersolidus liquid phase sintering at 1280 ℃, the relative density of composites is 94.17%, the hardness is 49.2HRC and the bending strength is 980 MPa. In the pin and disc wear test, the wear resistance of the composites is 1.52 times than that of the single high chromium cast iron materials, and the wear mechanism is abrasive wear and slight oxidation wear.

Keywords

• tic/hcci
• vacuum sintering
• microstructure
• mechanical property
• friction and wear