NanoTi - Grain refinement of Ti-6Al-4V wire to enable Aerospace DED AM

机身制造商使用大型机械加工钛部件，但他们的制造方法导致材料利用效率低下。大多数(通常超过80%)用于制造零件的高价值、有血统的材料被加工成低价值的碎屑，必须报废，或者通过能源密集型和环境成本高昂的工艺回收。该行业使用术语购买与飞行比率(BTF)来量化制造该部件所购买的材料的质量，并与成品部件的质量进行比较。对于约25公斤的大型部件，BTF为5：1到10：1是典型的，但对于几种宽体结构，BTF为20：1也可以看到。AM提供了一种制造路线，BTF为3：1，通常为2：1，并优化了工艺。粉床添加剂制造用于质量最大为~3公斤的部件，使用粉末原料，但速度太慢，尺寸有限(最大实际尺寸为&lt；1m)，不适用于较大的部件。对于较大的元件，DED(定向能量沉积)是AM方法；通过将线材或粉末原料送入沉积头，通过操纵沉积头来逐层形成元件。这种AM方法能够解决大型(例如25公斤以上)部件，减少机身业务的金属消耗，从而降低成本和对环境的影响。从材料的角度来看，Ti6Al4V合金被公认为机身制造商的“主力”，占全球钛产品市场份额的近一半。然而，当使用DED AM沉积Ti6Al4V时，Ti6Al4V会出现道次间柱状晶长大，这严重降低了其力学性能。问题是如何制造一种合适的、低成本的原料材料来实现这一点。Epoch线材有一种独特的线材生产方法，专为超导线材制造而开发，提供了一种精细而可靠的生产方法。在该项目中，我们将生产和评估一系列掺杂线材，并使用全面的DED AM方法(Arc/WAAM、激光和电子束DED)建立它们的AM能力--这可能为航空航天部门提供关键投入，以释放AM在飞机制造中的全部潜力。

Airframe fabricators use large machined titanium components but their manufacture methods makes inefficient use of material. Most (typically more than 80%) of the high value, pedigree material purchased to make a part is machined away into low-value swarf, that has to be scrapped, or recycled through energy intensive and environmentally costly processes. The industry uses the term buy-to-fly ratio (BtF) to quantify the mass of material purchased to make the part, compared with the mass of the finished component. For large components of ~25kg a BtF of 5:1 to 10:1 is typical, but for several wide-body structures BtF of \>20:1 are also seen.AM offers a manufacturing route that can be significantly more material efficient with BtF of 3:1, and typically <2:1 with an optimised process.Powder bed Additive Manufacturing is being used effectively for components of up to ~3kg mass, using powder feedstock, but is too slow and limited in dimension (maximum practical dimension is <1m) to be viable for larger components. For larger components, DED (directed energy deposition) is the AM method; whereby wire or powder feedstock is fed into a deposition head, which is manipulated to form the component layer-by-layer. This AM approach is able to address large (e.g. 25+kg) components reducing the metal consumption of the airframe business, and consequently lower costs and environmental impact.From a material stand-point, Ti6Al4V alloy is recognised as the "workhorse" of airframe fabricators, and represents almost half of the market share of titanium products used worldwide. However, Ti6Al4V suffers from inter-pass columnar grain growth when deposited using DED AM -- which severely reduces its mechanical performance.It is well established that small additions of grain growth modifiers can offer such a solution; the issue has been how to make a suitable, low-cost, feedstock material that can deliver this.Epoch Wires has a unique wire production approach, developed for superconducting wire manufacture, that offers a way to finely and reliably offer such a production method.Within the project, we will produce and evaluate a range of doped wires and establish their 'AM-ability" using a full range of DED AM methods (Arc/WAAM, Laser and Electron Beam DED) -- potentially offering the aerospace sector a key input into unlocking the full potential of AM for aircraft manufacture.