Thermal control and uncertainty evaluation of thermo-mechanical properties of materials for industrial hot stamping productions

英国近三分之一的净温室气体排放来自汽车工业和公路运输，四分之一的碳足迹来自材料行业。车辆的轻量化设计对于通过适当使用材料、开发智能制造技术和改进生产实践（如热冲压）来减少二氧化碳排放至关重要。数据驱动的制造业需要通过称为多轴测试的专门方法测量材料的多方向性能，以在真实的寿命条件下拉伸一块材料直到断裂，因为大多数工程材料都是各向异性的。通过使用材料多轴数据和虚拟样机-用于设计/制造轻量化汽车部件的典型集成仿真技术，可以降低低碳制造的成本和时间。现有的材料多轴热机械测试方法复杂，成本高，并且不容易在高温下进行测试。Multi-X（伦敦帝国理工学院的一个分支机构）开发了新的测量仪器、算法和方法，用于在真实的制造条件下进行材料表征，以克服缺乏材料成形性数据的瓶颈，从而量化热冲压条件下的复杂应变状态，并提高产品设计和制造的能源效率。在该项目中，在Multi-X的测试过程中，将采用NPL最先进的设备对温度分布进行非接触式测量。它将能够监测温度场的热历史和空间均匀性，以准确表征材料的多轴热机械性能。将对测量温度和材料特性进行不确定性分析，以证明Multi-X创新测试方法的可靠性和稳健性。Multi-X为最终用户进行了一系列多轴测试，涵盖了通常用于轻型汽车零件热冲压生产的硼钢和铝合金。该项目将专注于对温度高达550 °C的铝合金进行热评估，成功的项目成果将提高领先的材料热机械测试技术的质量保证，最终目标是利用这项英国发明的技术，实现具有成本效益的轻型汽车部件制造。Multi-X的技术有潜力应用于广泛的其他领域，包括航空航天、火车、生物工程等，进一步开发市场。此外，它还可用于测量其他材料的多轴特性，例如，钛、镁、复合材料、组织、纺织品。

Almost one third of the UK's major contributions to net greenhouse emissions are from the automotive industry and road transport, and a quarter of the carbon footprint is from the materials sector. Lightweight design of vehicles is crucial in contributing to reducing CO2 emissions, by using materials appropriately, developing intelligent manufacturing technologies, and improving production practices, such as in hot stamping. The data-driven manufacturing industry requires multi-directional performance of materials to be measured by a specialised method, called multi-axial testing, to stretch a piece of material under real life conditions until fracture, given that most of engineering materials are anisotropic. By using material multi-axial data and virtual prototyping - the typical integrated simulation technology used for designing/manufacturing lightweight car parts, enables a reduction in cost and time in low carbon manufacturing.Existing material multi-axial thermo-mechanical testing methods are complicated, costly, and cannot be readily applied for testing at high temperature. New measurement instrumentation, algorithms, and methods for material characterisation under real manufacturing conditions, have been developed at Multi-X, a spin-off of Imperial College London, to overcome the bottleneck of the lack of material formability data to quantify complicated straining states under hot stamping conditions, and to improve the energy efficiency of product design and manufacture.Within the project, contactless measurement of the temperature distribution delivered by the state-of-the-art equipment at NPL will be implemented in the Multi-X's testing process. It will enable monitoring of the thermal history and spatial uniformity of temperature field for accurate characterisation of material multi-axial thermo-mechanical properties. An uncertainty analysis of the measured temperature and material properties will be performed to demonstrate the reliability and robustness of the Multi-X's innovative testing method. Multi-X has conducted a range of multi-axial tests for end-users, covering boron steel and aluminium alloys that are commonly used in hot stamping production of lightweight car parts. This project will concentrate on the thermal assessment of aluminium alloys up to a temperature of 550 °C.A successful project outcome will improve the quality assurance of the leading material thermo-mechanical testing technology, with the ultimate aim to exploit this UK-invented technology to enable cost-effective manufacture of lightweight car components. Multi-X's technology has the potential to be applied in a wide range of other sectors, including aerospace, train, bioengineering, etc., to further develop the market. Additionally, it can be applied to measure multi-axial properties of other materials, e.g., titanium, magnesium, composite, tissue, textile.