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

烧结是一种允许从金属粉末净成形生产零件的工艺。烧结的一个主要优点是它减少了对材料去除步骤的需求，例如机械加工，从而降低了成本，能源使用和材料浪费。当烧结应用于运输应用中的轻金属（例如钛）时，可以实现重量减轻和燃料消耗降低的额外好处。 在本研究中，我们将研究两种钛合金（Ti-6wt%Al-4wt%V和Ti-10wt%V-2wt%Fe-3wt%Al）的混合元素（BE）和中间合金（MA）烧结。在MA或BE烧结中，将商业纯（CP）Ti粉末与MA粉末（例如预合金化的60重量% Al/40重量%V粉末）或元素粉末（例如6重量%纯Al和4重量% V）混合以获得期望的合金组成。该粉末混合物被压实成近净形状，其通常在压实粉末之间具有占总部件体积的20至25%的孔隙。在烧结过程中，Al和V合金元素通过CP-Ti基质扩散，形成均匀的合金成分，同时有助于减少原始压实部件中存在的孔隙率。目前，使用大粒度CP-Ti粉末的最低成本烧结路线无法获得大多数工业应用所需的最终性能。这主要是由于烧结过程无法将原始孔隙率降低到低于2%的所需水平。将使用三种热分析工具的组合来产生对使用大CP-Ti粉末的Ti合金的MA和BE烧结的基本理解。从这项工作中获得的见解将用于通过烧结开发更具成本效益和更高性能的钛部件。这将增加这种轻金属在加拿大航空航天和汽车工业中的使用，有助于减轻重量，降低燃料经济性，并最终减少温室气体。研究成果的应用将有助于提高加拿大公司的全球竞争力，改善加拿大人的社会经济福祉。

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.