Development of advanced sintering processes using novel high temperature thermal analysis techniques

Sintering is a process which allows the net shape production of a part from metallic powder. A major advantage of sintering is that it reduces the need for material removal steps, such as machining, thus reducing costs, energy usage and material waste. When sintering is applied to lightweight metals (e.g. Titanium) for transportation applications, the added benefit of weight reduction and lower fuel consumption can be realized.

In this proposal, the production of two Titanium alloys (Ti-6wt%Al-4wt%V and Ti-10wt%V-2wt%Fe-3wt%Al) using blended elemental (BE) and master alloy (MA) sintering will be investigated. In MA or BE sintering, commercially pure (CP) Ti powder is mixed with either an MA powder (e.g. a prealloyed 60 wt% Al/40wt% V powder) or elemental powders (e.g. 6 wt% pure Al and 4 wt% V) to obtain the desired alloy composition. This powder mixture is compacted into a near net shape, which typically has pores between the compacted powders in the range of 20 to 25% of the total part volume. During sintering, the Al and V alloying elements diffuse through the CP-Ti matrix, creating a uniform alloy composition, while helping to reduce the porosity present in the original compacted part. Currently, the lowest cost route of sintering, using a large CP-Ti powder size, is unable to obtain the final properties needed for most industrial applications. This is primarily due to the inability of the sintering process to reduce the original porosity to the required level of less than 2%. A combination of three thermal analysis tools will be used to generate a fundamental understanding of MA and BE sintering of Ti alloys using large CP-Ti powders. The insight gained from this work will be used to develop more cost effective, and higher performance Ti parts through sintering. This will increase the use of this light metal in the Canadian aerospace and automotive industries, facilitating weight reduction, lower fuel economy and ultimately a reduction in greenhouse gases. The application of the research results will contribute to an increase in the global competitiveness of Canadian companies and an improvement of the socioeconomic well being of Canadians.