Three-Body Abrasive Wear Behavior of Cementite with Different Chromium Concentrations

Abstract

The abrasion-resistant properties of white cast iron, which is used as a wear-resistant material in many industrial applications, are affected by cementite properties. Hence, it is important to obtain an understanding of the mechanical properties and abrasive behavior of single-phase cementite. In this article, bulk cementite samples with 0, 3.01, 6.03, 8.22 and 9.76 wt% chromium were prepared using mechanical alloying and spark plasma sintering. Sample phase composition and mechanical properties were determined by X-ray diffractometry, microhardness testing and nano-indentation. When the chromium content was >6.03 wt%, bulk single-phase cementite was produced. The elastic modulus, elastic recovery and hardness increased with chromium content. When the chromium content was 9.76 wt%, the maximum microhardness was 1070.74 HV (Vickers hardness) and the maximum elastic modulus was 199.32 GPa. The cementite wear behavior was investigated using a three-body abrasive wear tester. Cementite with higher chromium content had a lower wear mass loss under a 3 kg load, which indicates that bulk cementite has an improved wear resistance. Short- and long-range plowing and chipping pits existed on the worn surface. Because a high-/low-chromium cementite composite structure was formed, this resulted in a significant decrease in worn surface roughness and chipping pit depth.