Abstract
Ti has merits as a strong solid solution hardener and a sintering enhancer for iron. In this study, transient liquid phase sintering has been applied to the Fe-Ti system for forming the high performance iron powder metallurgy materials with considering several third additive elements. Specimens were prepared from an atomized iron powder(-100mesh), Ti powder (-350mesh) and various alloying element powders such as Co, Ni and Si, followed by compacting under 686MPa and sintered at 1573K for 3.6ks in vacuum.
A 6% addition of Ni to the Fe-4%Ti system showed greater than a 85% increase in tensile strength and hardness, although elongation was decreased with increasing Ni content. This is attributed not only to the solid solution hardening by the uniform distribution of Ti and Ni but also to the spheroidization of pores. On the other hand, tensile strength of the Fe-Ti-Si systems increased with an increase in Si content, independing on Ti content as a result of forming the Ti rich intermetallic compound particles such as SiTi3 and Si3Ti5. Generally, addition of third alloying elements to the Fe-Ti system reduced the ductility, but only Co showed no influence on that because of remarkable enhancement of the sintering of Fe-Ti compacts.
