Analysis of Structure and Abrasion Resistance of the Metal Composite Based on an Intermetallic FeAl Phase with VC and TiC Precipitates

Abstract

Metal alloys with matrix based on an Fe-Al system are generally considered materials for high-temperature applications. Their main advantages are compact crystallographic structure, long-range ordering and structural stability at high temperatures. These materials are based on an intermetallic phase of FeAl or Fe3Al, which is stable in the range from room temperature up to the melting point of 1240°C. Their application at high temperatures is also beneficial because of the low cost of production, very good resistance to oxidation and corrosion, and high mechanical strength. The casting alloy the structure of which includes the FeAl phase is, among others, highaluminium cast iron. This study has been devoted to the determination of the effect of vanadium and titanium on the transformation of the high-aluminium cast iron structure into an in-situ FeAl-VC composite.

Shaping the Microstructure of High-Aluminum Cast Iron in Terms of the Phenomenon of Spontaneous Decomposition Generated by the Presence of Aluminum Carbide

“…If the phenomenon of the self-decay of high-aluminum cast iron is eliminated, a good and inexpensive material from the Fe-Al intermetallic group [10][11][12][13] could be created. To date, the method of minimizing or completely preventing the formation of the undesirable Al 4 C 3 phase in high-aluminum cast iron composites (>19% Al) has been investigated [1,5,11]. The absence of aluminum carbide in these castings significantly improves the mechanical strength.…”

“…One further issue remains, i.e., the replacement of the Al 4 C 3 carbide with another carbide with the use of carbide-forming elements, e.g., Ti, V, W. Such treatment may result in the complete elimination of the Al 4 C 3 carbide by producing another with a changed shape. The compact shape of the new carbide, e.g., TiC, VC, WC, will not cause excessive stress during free shrinkage, contributing to the durability of the casting [5,11].…”

An Evaluation of the Microstructure of High-Aluminum Cast Iron in Terms of the Replacement of Aluminum Carbide with Titanium Carbide or Tungsten Carbide

“…The mass wear rate Vw was calculated, as determined by the tangent of the angle of inclination of the tangent line to the curve in the second hour of the abrasion wear test [15]: Vw =A . B .…”

“…For high-chromium steel (A), the weight loss was the greatest, i.e., 0.85 g [15]. For chromium cast iron (B)-with the chemical composition [% mass]: 3.35% C; 1.5% Si; 0.63% Mn; 21.10% Cr, the weight loss of the sample was 0.33 g and for sample (C) of high aluminum cast iron with vanadium addition was 0.36 g. Due to the graphite present in the microstructure in sample (D), acting in this case as a natural lubricant, the test results are not fully reliable, but confirm the high resistance of this material to abrasive wear.…”

“…For high-chromium steel (A), the weight loss was the greatest, i.e., 0.85 g [15]. For chromium cast iron (B)-with the chemical composition [% mass]: 3.35% C; 1.5% Si; 0.63% Mn; 21.10% Cr, the weight loss of the sample was 0.33 g and for sample (C) of high aluminum cast iron with vanadium addition was 0.36 g.…”