SBIR Phase I: Casting Technology for High Temperature Titanium Alloy Lattice Block Structures

这个小型企业创新研究(SBIR)一期项目将通过铸造生产高温钛合金格子块材料(LBM)。晶格块体材料是一种创新的周期性蜂窝材料，其优异的力学性能来自于高度有序的内部三角形结构，而不是母体材料的性质。到目前为止，这些工程材料已经成功地铸造了许多黑色金属和有色金属。对于钛合金，只做了有限的工作，主要是在中等温度范围内使用的成分。随着高温钛合金(如贝塔钛)越来越多地成为高温机身和航空发动机的首选材料。贝塔钛合金很难铸造成复杂的薄壁形状，这是由于各种因素，包括在截面中心线形成收缩的倾向。因此，一种独特的铸造技术被开发出来，使生产高温钛合金LBM成为可能。潜在的应用包括飞机和航天器结构，包括热保护系统，以及飞机和汽车发动机部件。这项技术产生的更广泛的影响将是钛-LBM在未来航空航天和非航空航天系统中使用的重量和成本降低的机会。通过热成形、扩散连接和超塑性成形，Ti-LBM可以用来取代更昂贵的蜂窝和由薄板/薄片组成的夹层结构。由高温钛合金制成的LBM将能够取代低温镍基高温合金，从而显著减轻重量。

This Small Business Innovative Research (SBIR) Phase I project will produce high temperature titanium alloy lattice block materials (LBM) via casting. Lattice block materials are innovative periodic cellular materials that derive their outstanding mechanical performance from a structure of highly ordered internal triangles, rather than the properties of the parent material. To date, these engineered materials have been successfully cast for a number of ferrous and non-ferrous metals. For titanium alloys, only limited work has been done, mainly on compositions that are used at moderate temperature ranges. As higher temperature titanium alloys such as beta titanium are increasingly becoming the materials of choice for high temperature airframe and aero engine applications. Beta titanium alloys are extremely difficult to cast into complex and thin-walled shapes due to factors, including a propensity for forming shrinkage at the centerline of sections. Thus, a unique casting technology is being developed to make it possible to produce high temperature titanium alloy LBM. Potential applications include aircraft and spacecraft structures, including thermal protection systems, as well as aircraft and automotive engine components.The broader impacts derived from this technology would be Ti-LBM opportunities for weight and cost reduction for use in in future aerospace and non-aerospace systems. Ti-LBM can be used to replace more expensive honeycomb and sandwich structures built up from thin sheets/foils via hot forming, diffusion bonding, and superplastic forming. LBM made from high temperature Ti alloys would be capable of replacing lower temperature Ni-based superalloys for significant weight savings.