Experiment and modeling of mechanical properties on iron matrix composites reinforced by different types of ceramic particles

摘要

The strength, Young's modulus and hardness properties of iron matrix composites reinforced by different types of ceramic particles (SiC, Cr_3C_2, TiC and Ti(C, N)) prepared by the dynamic temperature control direct current heating technology were investigated experimentally. The stress-strain curves of the different composites and stress in reinforcing particles were simulated by Eshelby approach modeling in order to interpret the experiments and to reveal the strengthening mechanisms. It was found that SiC reinforcing particles show the strongest effect on improving the strength of the composite among the four types of reinforcements experimentally. The theoretical analysis exposes the reason as its higher fracture toughness and hardness as well as a limited decomposition to increase matrix strength. The strength of the four composites all presents a maximum value at 10% volume fraction and the reason can be interpreted by that glomeration of particulate reinforcements happens remarkably only when the fraction is over 10%. The stress-strain curves by the modeling agree well with those of the experiments on TiC/Fe and Ti(C, N)/Fe composites but not on SiC/Fe and Cr_3C_2/Fe composites. This suggests that the strengthening mechanisms of the composites rely not only on load sharing of the reinforcements but also on increasing matrix strength.