Cyclic Deformation and Damage Mechanisms in additive manufactured Ti-6Al-4V with Graded Microstructures

与传统制造工艺相比，相加制造(AM)，也被称为3D打印，已被广泛认为能够提供一系列物流、经济和技术优势。例如，AM为航空航天部门开辟了新的商机，因为它缩短了上市时间，提高了购买与飞行比率，特别是在钛合金方面。然而，各行各业广泛采用AM来生产金属工程零部件仍然是一个挑战。对AM制造材料的可靠性缺乏了解，以及对工程结构完整性的相关担忧，已被认为是成功将这一前景光明的制造工艺商业化的障碍之一。Ti-6Al-4V是最流行的钛合金，广泛应用于航空航天应用。罗尔斯-罗伊斯公司在德比已应用AM技术修复航空发动机叶盘(叶片盘)，美国GE航空公司已为LEAP航空发动机开发AM制造的燃油喷嘴。随着AM进入更重负荷的终端部件的生产，特别是在航空航天部门，更好地了解AM部件/部件在循环(疲劳)载荷下的机械行为是至关重要的。这需要为包含AM制造的零部件的安全关键工程系统开发基于机械的寿命评估程序。通过与英国世界著名的AM制造技术中心(MTC)和最终用户(劳斯莱斯PLC)积极合作，该项目将开发一个经过实验验证的基于微观结构的模型，该模型可以在对AM制造的Ti-6Al-4V进行疲劳裂纹萌生的寿命预测时采用。

Additive manufacturing (AM), also called 3D printing, has been widely recognised to be capable of offering a range of logistical, economic and technical advantages when compared with conventional manufacturing processes. For example, AM has opened up new business opportunities for the aerospace sector because of its reduced time-to-market and higher buy-to-fly ratio, in particular for titanium alloys. However, the widespread adoption of AM by industries for the production of metallic engineering parts/components remains a challenge. Lack of knowledge about the reliability of AM-built materials and associated concerns about engineering structural integrity has been identified as one of the hurdles to successfully commercialise this promising manufacturing process.Ti-6Al-4V is the most prevalent titanium alloy and is widely used in aerospace applications. Rolls-Royce PLC at Derby has applied AM technologies to repair aero-engine BLISKS (Bladed-Disks) and GE Aviation in the USA has developed AM-built fuel nozzles for the LEAP aero-engines. With AM moving into the production of more heavily loaded end-use components, particularly within the aerospace sector, improved understanding of the mechanical behaviour of AM parts/components under cyclic (fatigue) loading is essential. This requires the development of a mechanistic based lifetime assessment procedure for safety-critical engineering systems that contain AM-built parts/components.By engaging actively with both the UK's world-renowned AM manufacturing technology centre (MTC) and an end-user (Rolls-Royce PLC), this project will develop an experimentally-validated microstructure-based model that can be adopted when undertaking a lifetime prediction against fatigue crack initiation in AM-built Ti-6Al-4V.