Microstructure and wear characteristics of ATZ ceramic particle reinforced gray iron matrix surface composites

Abstract

G ray iron is one of the most common cast iron and widely used as a kind of cast material due to its low cost, outstanding castability and excellent machinability [1,2] . However, the poor wear resistance is a fatal weakness for the gray iron. As we all know, wear is one of the main failure modes of metallic materials and about seventy percent of mechanical damage is caused by various forms of wear and tear. The grinding loss not only consumes a lot of metal material, but also causes huge economic loss and heavy casualties. So revealing the mechanism and improving the wear resistance of the gray iron matrix are significant.The ceramic particle reinforced metal matrix composites (CPRMMCs) can combine the advantages of ceramics and metals, and exhibit relative high strength and wear resistance, so they have attracted more and more attention [3][4][5][6] . Ceramic particles, such as wolfram Abstract:The alumina toughened zirconia (ATZ) ceramic particle reinforced gray iron matrix surface composite was successfully manufactured by pressureless infiltration. The porous preform played a key role in the infiltrating progress. The microstructure was observed by scanning electron microscopy (SEM); the phase constitutions was analyzed by X-ray diffraction (XRD); and the hardness and wear resistance of selected specimens were tested by hardness testing machine and abrasion testing machine, respectively. The addition of high carbon ferrochromium powders leads to the formation of white iron during solidification. The wear volume loss rates of ATZ ceramic particle reinforced gray iron matrix surface composite decreases first, and then tends to be stable. The wear resistance of the composite is 2.7 times higher than that of gray iron matrix. The reason is a combination of the surface hardness increase of gray iron matrix and ATZ ceramic particles and alloy carbides protecting effect on gray iron matrix.Key words: metal-matrix surface composites; pressureless infiltrating; particle-reinforcement; surface alloying; wear testing carbide (WC), alumina (Al 2 O 3 ), titanium carbide (TiC) and silicon carbide (SiC), are now commonly used as the particle reinforcement [7][8][9][10][11][12] . WC ceramic particle reinforced iron matrix surface composites were produced using the V-EPC infiltration casting process by Li et al., and the composites' wear resistance was 1.5-5.2 times higher than that of the high chromium cast iron [13] . WC ceramic particle with good wettability and high hardness was used in the research [10] , but its higher price and the greater difference of thermal expansion coefficient from that of iron limit its use in the large scale production. Alumina toughened zirconia (ATZ) ceramic is becoming an important reinforcement particle to iron and steel because of its great performance/ price ratio, high hardness, high fracture toughness, and comparable thermal expansion coefficient [14] .ZrO 2 -Al 2 O 3 ceramic particle reinforced Cr25 matrix composites were fabricated using the infiltration casting process by Zheng et ...

Casting Defect and Process Optimization of Steel Crossing

“…Dengyue SUN, 1) Ruihao LV, 1) Jiuming XIE 2) and Shimin XU 1) * 1) National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao, 066004 China. 2) School of Mechanical Engineering, Tianjin Sino-German University of Applied Sciences, Tianjin, 300350 China.…”

“…Actually, a detailed study and analysis of crossing taking into account different fever risers and nonlinear material properties have not been carried out so far. 6) Considering the nonlinear material characteristics, the matching relationship between open and blind risers and castings, a nonlinear finite element model of high manganese steel has been developed in this study. An innovative pouring method of velocity attenuation is proposed based on ProCAST Software to make the simulation closer to the real situation.…”