Effect of Ti / Al Alloying on Microstructure and Mechanical Properties of U-5.5Mo Alloy

Abstract:

An experimental set-up was designed for measuring the self-field losses of Bi2223/Ag HTS tapes using a transport current method. Ti/Al was introduced into U-5.5Mo alloy by induction melting, and a new alloy U-Mo-Ti/Al is obtained in this way, its microstructures and properties are controlled by quenching and heat treatment of aging. The relationship between the composition, distribution and properties of precipitates was analyzed, the effect of Ti/Al alloy elements on the mechanical properties of U-5.5Mo alloy was investigated as well. It is found that added trace element Ti has obvious effect of solution strengthening on the alloy of U-5.5Mo. The mechanical properties of U-Mo-Ti ternary alloy can be greatly improved by low temperature aging. It can promote the formation of stable multi-component intermetallic compounds rich in titanium and aluminum in U-Mo-Ti-Al quaternary alloy under high temperature by adding trace element Al, multitudes of irregular continuous distribution of the trace element in the matrix and grain boundary have significant precipitation strengthening effect on the alloy, as a result, the strengthen of U-Mo-Ti-Al quaternary alloy is greatly improved while the plasticity almost decreases to zero.

Key words:aging treatment; solution strengthening; precipitation strengthening; mechanical properties