Effect of iron powder content on microstructure and mechanical properties of Al2O3p/high manganese steel composites prepared by casting infiltration

Abstract

Al _2 O _3 p/high-manganese steel-matrix composites were successfully fabricated by gravity casting infiltration, with iron powder added in the preforms to adjust the Al _2 O _3 p fraction. The effects of the iron powder content (38, 48, and 55 wt%) on the microstructures and mechanical properties of the composites were investigated. With the increase in the iron powder content in the preform, the Al _2 O _3 p fraction decreased (57–38 vol%), while the hardness and compressive strength of the composite gradually increased. The highest compressive strength was 1000.3 MPa (55-wt% iron powder). The highest work hardening rate (55-wt% iron powder) well reflected the synergistic effect between the matrix and reinforcement to prevent dislocation movement. The water glass binder formed thick interface layers between Al _2 O _3 p and matrix, which transformed the Al _2 O _3 /metal interface bonding from mechanical bonding to metallurgical bonding. A too thick interface layer deteriorated the mechanical properties of the composites.

Keywords

• Al2O3
• microstructure
• mechanical properties
• steel matrix composites
• Al2O3
• microstructure