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，但他们的制造方法使材料的使用效率低下。大多数（通常超过80%）为制造零件而购买的高价值、优质材料被加工成低价值的屑，这些屑必须被废弃，或通过能源密集型和环境成本高的工艺进行回收。该行业使用术语“买到飞比”（BtF）来量化制造零件所需购买的材料的质量，并与成品部件的质量进行比较。对于~25kg的大型部件，典型的BtF为5:1至10:1，但对于一些宽体结构，也可以看到BtF为20:1。增材制造提供了一条制造路线，可以显著提高材料效率，BtF为3:1，优化工艺通常<2:1。粉末床增材制造正在有效地用于高达~3kg质量的部件，使用粉末原料，但速度太慢，尺寸有限（最大实际尺寸<1m），无法用于较大的部件。对于较大的部件，DED（定向能沉积）是增材制造方法；电线或粉末原料被送入沉积头，该沉积头被操纵成一层一层地形成组件。这种增材制造方法能够解决大型（例如25公斤以上）部件的问题，从而减少了机身业务的金属消耗，从而降低了成本和环境影响。从材料的角度来看，Ti6Al4V合金被认为是机身制造商的“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会出现通道间柱状晶粒生长，这严重降低了Ti6Al4V的力学性能。众所周知，少量添加晶粒生长调节剂可以提供这样的解决方案；问题是如何制造一种合适的、低成本的原料来实现这一目标。Epoch Wires拥有一种独特的导线生产方法，专为超导导线制造而开发，提供了一种精细可靠的生产方法。在该项目中，我们将生产和评估一系列掺杂导线，并使用全方位的DED AM方法（电弧/WAAM，激光和电子束DED）建立其“AM能力”——可能为航空航天部门提供关键输入，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.