增材再制造机械零件服役寿命预测方法及实验研究

Life prediction is a technological means to guarantee quality and service safety of additive remanufacturing mechanical parts in the frontier equipment. It is also an important content for the study of basic theory of remanufacturing. The project will study lift prediction theory of additive remanufacturing mechanical parts and its experimental method. Firstly, a theoretical method of life prediction for additive remanufacturing mechanical parts is developed based on fracture mechanics and damage accumulation theory. Meanwhile, a mapping function between additive remanufacturing process and life is introduced into this method aims to describe the influence from the remanufacturing process. Secondly, an analysis experiment is carried out to reveal the influence rule of additive manufacturing process on service life of remanufacturing parts, and then a mapping function between additive manufacturing process and service life is established. Then, an analytic method of loads coupling relationship of remanufacturing parts under complex working environment are proposed based on load’s characteristics. Finally, the proposed life prediction method of additive remanufacturing mechanical parts is validated with application research on core parts of the frontier equipment（e.g. heavy-duty gear and impeller）. The project is expected to form a set of new methods towards service life prediction of additive remanufacturing mechanical parts. Providing theoretical and technical support to evaluate the safety performance of additive remanufactured parts situates real work environment. It is great significance to remanufacturing industry development and broad application prospects in china.

增材再制造机械零件服役寿命预测是高端装备再制造零件质量控制和服役安全性能保障的根本手段，属于再制造基础理论研究的重要内容。本项目研究增材再制造机械零件服役寿命的预测理论及实验方法。首先，以断裂力学和损伤累积理论为基础，引入增材再制造工艺寿命映射函数，构建增材再制造机械零件服役寿命预测的理论方法；其次，开展增材再制造工艺寿命影响实验，揭示增材再制造工艺对机械零件服役寿命的影响规律，建立两者之间的映射函数关系；然后，分析增材再制造零件服役载荷特性，建立一种多工况载荷及耦合环境下的机械零件再服役动静态载荷解析及实验方法；最后，以高端装备核心零件的增材再制造为工程背景，对所提出的服役寿命预测方法进行实践验证和应用研究。本项目预期形成一套面向增材再制造机械零件服役寿命预测的新方法和技术手段，为再制造零件可服役性和安全性评判提供理论和技术支撑，对我国再制造产业发展具有重要意义和广阔的应用前景。

我国是机械装备的制造大国与消费强国，机械装备再制造产业在我国大有可为。再制造后的机械零件是否有足够寿命满足新的生命周期和在复杂工况下是否具备足够的服役安全性能已成为再制造迫切需要解决的关键问题，亦是再制造市场和消费者关注的焦点。与新制造零件相比，再制造零件服役寿命预测或安全性能评估方面缺乏直接可用的理论模型，增材再制造工艺修复时必然产生多组元、高紊乱的材料特性且对其服役寿命影响尚不可知，再制造零件真实服役载荷谱测量困难且再制造过程还引入新的再制造工艺特征载荷及其耦合效应，这些导致再制造机械零件服役寿命评估比较困难。那么如何进行再制造机械零件服役寿命预测，为再服役安全提供理论依据已然成为当前亟需解决的科学问题。.在这种背景下，本项目以高端装备核心零件的增材再制造为工程背景，展开激光增材再制造机械零件服役寿命预测方法及实验研究。搭建了增材再制造工艺试验和服役寿命测试的实验系统平台并研制了相关实验辅助装置，探讨了激光增材再制造工艺优化方法，获得了不锈钢、铁基和镍基等粉末激光熔覆工艺优化方法以及低性能母材上激光熔覆高性能合金的组织形态、显微硬度和工艺残余应力分布特性等基础数据，通过理论及实验方法对再制造机械零件的载荷分析，获得了工艺载荷分布形式以及工作载荷特性，建立了一种基于服役载荷和再制造工艺的寿命预测模型及仿真方法。.增材再制造机械零件寿命预测是对机械零件寿命预测理论与技术的拓展与延伸，为再制造零件服役机理分析、服役安全性能评价提供理论和方法支持，是对再制造工程基础理论体系的有机补充和完善，具有科学意义和产业应用前景。特别是，研究成果不仅可用于机床、车辆、石化、矿山等行业，而且可用于坦克、舰船、航空、航天等国防领域的零部件战场即时修复及修复后的强度和安全性评估。因此，开展增材再制造机械零件寿命预测工作具有重要的研究价值。