Effects of Consolidation Process on the Microstructure and Mechanical Properties of ODS Ferritic Alloy

摘要

The oxide-dispersion-strengthened (ODS) ferritic alloy powders (Fe-14Cr-3Al-2W -0.1Ti-0.35Y_2O_3) were prepared by mechanical alloying (MA) at a rotation speed of 720 rpm for 24 h. All the elements were mixed homogenously in the powder, and Cr and Al dissolved in a-Fe after MA. The bulk samples were produced by spark plasma sintering (SPS) at 950 °C and 50 MPa and by hot isostatic pressing (HIP) at 1150 °C and 130 MPa, respectively. The SPS sample showed a tensile strength of 730 MPa and a poor ductility due to the existence of pores in microsize. The HIP sample had a high tensile strength of 980 MPa, yield strength of 710 MPa and elongation of 10.3 %. The excellent mechanical properties of the HIP sample was due to the small grain size of the matrix of about 400 nm and the fine oxide particles of 5-40 nm.