Bcc-superalloys: Engineering Resilience to Extreme Environments

核聚变、第四代裂变反应堆和航空航天燃气轮机对我们未来的能源生产和运输至关重要。它们在高温下的运行需要使用各种先进材料。为了承受这些极端环境，材料需要高熔点，高温强度和环境抗性，并且对于核，耐辐照性。为了提高效率，减少燃料的使用，以及提高性能，设计寿命和安全性，有很强的环境和经济动机来进一步提高所使用材料的温度能力。然而，虽然每年都在不断改进，但温度的上升越来越难以实现。在本提案中，通过实现基于(1)钨，(2)钛和(3)钢的新型体心立方（bcc，一种原子晶体结构）高温合金，寻求温度能力的逐步变化，用于核聚变和第四代裂变反应堆以及航空航天燃气涡轮发动机的极端环境。我将建立一个紧密的工业、国家和国际学术合作伙伴网络，使这些先进材料从概念到规模的转化成为可能。这些合作将分为bcc-高温合金工作包：（WP1）钨，引入Culham聚变能中心（CCFE）和悉尼ANSTO，研究核聚变和第四代裂变；（WP2）钛，引进TIMET和劳斯莱斯，用于航空发动机，以及苏黎世联邦理工学院，用于薄膜基合金的发现；（WP3）钢铁公司，引进劳斯莱斯的燃气/蒸汽涡轮机，以及杜塞尔多夫Max-Planck-Institut f<e:1> r Eisenforschung（钢铁研究，MPIE）的先进特性和钢铁专业知识。Bcc高温合金包括金属基体，其中原子排列成Bcc晶体结构，通过形成高强度有序的Bcc金属间化合物（例如fe或NiAl）的沉淀来增强。这与当前面心立方（fcc）镍基高温合金中使用的策略相似。然而，改变基体金属的晶体结构，从而也改变强化金属间化合物，代表了一种根本性的重新设计，需要发展新的认识。使用bcc耐火金属、钛基或钢基高温合金的主要优点是它们的熔点更高，这就有可能提高工作温度，并大大降低钢的成本。然而，晶体结构的改变需要一种全新的设计策略。虽然对bcc高温合金的有限研究表明它们具有吸引人的强度和抗蠕变性，但它们的低延展性阻碍了它们的发展。在此期间，我将深入研究高温合金的多种延展性策略，以提高其技术准备水平（TRL），从而消除目前商业化的障碍。系统的调查将由我本人、2名研究员（RF）、技术人员和项目允许的博士生，以及项目合作伙伴（CCFE、TIMET、劳斯莱斯、ANSTO、苏黎世联邦理工学院和MPIE）的工作人员进行。博士研究生将进行合金开发：WP1的钨合金50%由CCFE支持，WP2的钛合金50%由CCFE支持，两名学生，其中一名由TIMET资助，另一名由劳斯莱斯资助，第四所由大华银行资助的WP3由劳斯莱斯工业监督。这两名RF和技术人员将与这些学生一起从事合金开发和表征工作，但也会进行更详细的调查，其中一名RF专注于辐射损伤机制，另一名RF专注于变形机制，两者都使用先进的显微镜和微观力学，相关学生将逐步接受培训。

Nuclear fusion, Generation IV fission reactors and aerospace gas turbines are critical to our future energy generation and transportation. Their operation at high temperatures necessitates construction from a variety of advanced materials. In order to withstand these extreme environments materials require high melting points, high temperature strength and environmental resistance, and, for nuclear, irradiation resistance. There are strong environmental and economic incentives to yet further increase the temperature capability of the materials used, in order to improve efficiency to reduce fuel use, as well as for improve performance, design life and safety. However, while iterative improvements are being made year on year the temperature gains are becoming ever harder to realise. In this proposal a step change in temperature capability is sought by the realisation of a new class of body-centred-cubic (bcc, an atomic crystal structure) superalloys based on (1) Tungsten, (2) Titanium, and (3) Steel, for the extreme environments of nuclear fusion and gen IV fission reactors as well as aerospace gas turbine engines.I will create a close network of industrial, national and international academic partners, that will enable translation of these advanced materials from concept through to scale-up. The collaborations will be split across the bcc-superalloys Work Packages: (WP1) Tungsten, bringing in Culham Centre for Fusion Energy (CCFE), and ANSTO Sydney, toward nuclear fusion and Gen IV fission; (WP2) Titanium, brining in TIMET and Rolls Royce, for aero-engines, as well as ETH Zurich for thin film based alloy discovery; (WP3) Steel, bringing in Rolls Royce, for gas/steam turbines, and the Max-Planck-Institut für Eisenforschung (Iron Research, MPIE) Dusseldorf for advanced characterisation and steels expertise.Bcc superalloys comprise a metal matrix, where the atoms are arranged in a bcc crystal structure, which are reinforced by forming precipitates of high strength ordered-bcc intermetallic compounds (e.g. TiFe or NiAl). This has parallels to the strategy used in current face-centred-cubic (fcc) nickel-based superalloys. However, changing the base metal's crystal structure, and therefore also the reinforcing intermetallic compound, represents a fundamental redesign and necessitates the development of new understanding. The key advantage of using a bcc refractory-metal-, titanium-, or steel- based superalloy is their increased melting point(s), which give the possibility of increased operating temperatures, as well as greatly reduced cost for the case of steels. However, the change in crystal structure requires a fundamentally new design strategy. While the limited investigations into bcc superalloys have indicated that they have attractive strength, and creep resistance, they have been held back by their low ductility. During this fellowship, I will thoroughly investigate multiple ductilisation strategies on bcc-superalloys to advance their technology readiness level (TRL) and so remove the current barrier to their commercialisation. Investigation of the systems will be undertaken by myself, the 2 Research Fellows (RF), technician, and PhD students allowed for by the programme, as well as staff time from the project partners (CCFE, TIMET, Rolls Royce, ANSTO, ETH Zurich and MPIE). The PhD students will undertake alloy development between: WP1 on Tungsten alloys 50% supported by CCFE, WP2 on Titanium, two students, one 50% by TIMET and a second 50% by Rolls Royce, with a fourth school funded by UoB on WP3 industrially supervised by Rolls Royce. The two 2 RFs and technician would work in alloy development and characterisation alongside these students, but also perform more detailed investigations, with one RF focussed on irradiation damage mechanisms, and the second RF on deformation mechanisms, both using advanced microscopy and micromechanics on which the related students would be progressively trained.