大型航空热锻模增材复合制造修复技术及应用

Additive Composite Manufacturing Repair Technology and Application of Large Aerospace Hot Forging Die

为了提高大型航空热锻模的服役寿命、降低其制造成本,将电弧熔丝增材制造技术应用于大型航空热锻模的再制造修复。首先,利用数值仿真技术得到模具在服役时的温度场和应力场,并根据其分布状态设计了模具的三层梯度结构,实现原模具基体上覆盖少量具有较好高温红硬性材料的目的,进而在降低模具再制造成本的同时提升模具寿命。其次,针对三层结构中的过渡层和强化层,分别设计了铁基和钴基材料。分析表明在室温下过渡层材料的强度最高、硬度最大、塑性最差,强化层材料在室温下的塑性和强度都略高于基体材料;在650℃高温下,强化层材料的强度最高,并且显著高于过渡层材料和基体材料。这种分层材料的设计,能够保证模具在服役时候表面强化层在高温下能够抵抗磨损和塑性变形,而过渡层温度较低又能提供强有力的强度支撑。最后,对某钛合金一梁大型锻模、超高强度钢起落架大型锻模进行了再制造修复验证,经多批次生产的考核验证,比传统方法制造的模具寿命提高了数倍,再制造锻模未出现裂纹、塑性变形等缺陷,表面层保持良好,变形量较原5CrNiMo模具小得多。

In order to improve the service life of large aerospace hot forging die and reduce its manufacturing cost,the arc fuse additive manufacturing technology has been applied to the remanufacturing repair of large aerospace hot forging die.Firstly,the temperature field and stress field of the mold in service have been obtained by numerical simulation technology,and the three-layer gradient structure of the mold has been designed according to the temperature field and stress field,so that the low-cost mold base has been covered with a small amount of high-temperature red-hardened material.The purpose is to increase the life of the mold while reducing the cost of mold remanufacturing.Secondly,iron-based and cobalt-based materials have been designed for the transition layer and the strengthening layer in the three-layer structure,respectively.The analysis shows that the strength of the transition layer material is the highest,the hardness is the highest,and the plasticity is the worst at room temperature,and the plasticity and strength of the reinforcement layer material at room temperature are slightly higher than those of the base material.At a high temperature of 650℃,the strength of the reinforcement layer material is the highest,and significantly higher than transition layer materials and base materials.The design of this layered material can ensure that the surface strengthening layer of the mold can resist wear and plastic deformation at high temperatures when the mold is in service,and the transition layer has a lower temperature and can provide strong strength support.Finally,the remanufacturing and repairing verification has been carried out on a titanium alloy one-beam super-large forging die and a super-high-strength steel landing gear super-large forging die.After the verification of multiple batches of production,the life of molds has been increased several times than that manufactured by traditional methods.There are no defects such as cracks and plastic deformation in the remanufacturing forging die,the surface layer is kept well,and the deformation amount is very small compared with the original 5CrNiMo die.