Abstract
The Pseuso-HIP reactive sintering (or PseudoHlP-SHS) process which is based on Pseudo-HIP and SHS (Self propagating High-temperature Synthesis) has opened a new fabrication route for producing intermetallic compound materials. The reactive sintering process of TiAl intermetallic compound in which PseudoHIP-SHS was used is presented in this paper. From our results, it was shown that Pseudo-HIP Process effectively utilized the heat release and the transient liquid phase involved in SHS for the densifing the compacts. After the SHS process, the relative density of the compacts set in the Pseudo-HIP equipment was increased to more than 99% as the Pseudo-HIP temperature was increased. It was possible for microstructure control of duplex or fully lamellar structure to be conducted under atmospheric pressure after the Pseudo-HIP reactive sintering, and the strength of a duplex structure controlled under atmospheric pressure resulted in the strength approximately equal to that controlled under the mechanical pressure of the Pseudo-HIP. Following these results, near-net shaping of a valve spring retainer for an automobile engine by the use of PseudoHlP-SHS was tried. Consequently, the results of motoring tests demonstrated that the spring retainer increased the maximum engine revolution because of the 40% reduction in weight of the current Fe alloy used in the engine.
