Mechanical and microstructural behaviour of a particulate reinforced steelfor structural applications

Low density, high modulus, and potentially improved wear resistance are the major benefits of a ferrous composite material. A BS S.156 (4%NiCrMo) gear steel reinforced with 15 vol.-% titanium diboride particles has been demon strated for possible high performance structural applications. This composi te has been produced by a powder metallurgy/mechanical milling processing r oute,to give a homogeneous distribution of fine reinforcement particles. Th e composite tensile strength was 90% of the matrix in the fully heat treate d condition, with ductility of up to 6%, However, martensite formation and hence the hardenability was found to be suppressed in the composite. A fati gue study indicated that the titanium diboride particles did not appear to contribute to crack initiation in the composite. MST/4531.