GOALI: Influence of Length-Scale on Diffusion During FAST (Field-Assisted Sintering Technology)

钛及其合金代表了一个重要的材料家族，其提供能量效率沿着机械和环境优点，但主要由于生产成本高而仅看到有限的应用。 电场辅助烧结技术，有时称为放电等离子烧结，是一种用于粉末或颗粒固结的新工艺，与传统方法相比具有成本优势。 该资助机会与工业学术联络（GOALI）项目的团队将有助于对钛和钛粉场辅助烧结过程中分子扩散行为的基本理解，这将使这些材料的成本效益制造成为可能，同时保持材料属性，如高强度，低密度和环境惰性。 这些发现将影响汽车和航空航天行业。合作的大学-工业研究团队将教育大学生，以及提供推广活动，以吸引高中生到engineering careers. Available的多组分系统中的扩散数据一直稀缺，由于扩散分析的复杂性和相互扩散系数的组成的依赖。 这阻碍了对商业上重要的材料中遇到的三元或更高阶系统的烧结动力学的精确建模。 研究团队将生成钛-铝-铌系统的三元互扩散系数，这是汽车和航空航天应用的重要材料系统。 在场辅助烧结过程中存在电场的情况下，相平衡可以改变，从而在加工过程中产生新相或消除某些相。施加的电场和微观结构的长度尺度的影响将通过一组实验和模拟，将提供深入的热力学和动力学的相互扩散和相平衡/所选材料系统的转换进行评估。有了这一见解，钛合金可以设计和制造所需的性能，成本低于目前的可用。

Titanium and its alloys represent an important family of materials providing energy efficiency along with mechanical and environmental advantages but have seen only limited application primarily due to the high cost of production. Electric field-assisted sintering technology, sometimes called spark plasma sintering, is a novel process for the consolidation of powders or particulates that offers cost advantages over conventional approaches. The team of this Grant Opportunity for Academic Liaison with Industry (GOALI) project will contribute to the fundamental understanding of molecular diffusion behavior during field-assisted sintering for titanium and titanium powders that will enable cost-effective manufacturing of these materials while maintaining material attributes such as high strength, low density and environmental inertness. The findings will impact both the automotive and aerospace industries. The collaborative university-industry research team will educate university students as well as provide outreach activities to attract high school students to engineering careers.Availability of diffusion data in multicomponent systems has been scarce due to the complexity of diffusion analyses and the dependence of interdiffusion coefficients on composition. This has prevented accurate modeling of the kinetics of sintering for ternary or higher order systems encountered in commercially important materials. The research team will generate ternary interdiffusion coefficients for titanium-aluminum-niobium systems, an important material system for automotive and aerospace applications. In the presence of an electric field during field-assisted sintering, the phase equilibrium can be altered giving rise to new phases or eliminating certain phases during processing. The effects of an imposed electric field and microstructural length scale will be assessed through a set of experiments and simulations that will provide insight into the thermodynamics and kinetics of the interdiffusion and phase equilibria/transformation for the chosen material system. With this insight, titanium alloys can be designed and manufactured with desired properties at lower cost than is available today.