摘要
采用GH4169粉末对航空发动机材料GH4169合金进行激光修复试验,测试修复试样与母材试样的室温、高温拉伸性能、疲劳性能,将两者之间以及和材料标准进行对比,并进行组织分析。研究表明,在合适的工艺参数下,热影响区很窄,仅为0.1~0.2 mm,熔覆区冶金质量良好,未见明显空洞和熔合缺陷等;修复试样的室温拉伸强度达到1299 MPa,高温拉伸强度达到1069 MPa,与母材相当,且高于材料标准;塑性降为母材的50%;修复试样横向取样疲劳性能高于母材标准,纵向取样疲劳性能稍低于母材标准,但同属于一个数量级。激光修复后可控制零件的变形,保证零件的尺寸精度。零件修复后经X光探伤检测,内部无大于0.3 mm气孔,无聚集性缺陷,无裂纹等,质量满足验收要求。经装机考核验证,该激光修复技术适用于承受静载,服役温度不超过500℃的航空部件修复。
GH4169 alloy was a kind of age hardening nickel-iron based superalloy withγ"phase as the main strengthening phase.It had excellent comprehensive properties at high temperature,so it was widely used as crucial heated end integral parts in the aeroengine.With the sharp increasing repairing demand in these kinds of parts,especially in high precision repairing conditions,it was urgent to develop a targeted rapid and precise repairing technology.The test was based on the repairing of aeroengine prewhirl in highpressure turbine nozzle,due to assembly reasons,the deformation in the repairing process needed to be strictly controlled,this test focused on studying whether the microstructure characteristics and mechanical properties of the repaired samples meet the designed requirements,and the fatigue properties of the samples were tested as a supplementary basis for evaluating the feasibility of laser repairing,the deformation should be studied in this process.Samples were made through the laser cladding,and tensile properties at high temperature and low temperature and fatigue performance were tested to determine the optimal repairing parameters.Simulated specimen then was repaired with the optimal parameters,whose internal and external defects were detected,and installed in the engine to do long test evaluation.According to this,experimental evidences and engineering application evidences were provided for the laser repairing technology on the high temperature alloy under the same condition of aviation service.The repair matrix material was GH4169 blocks(forgings),the BLT-C600 three-dimensional forming laser system was used to stack the GH4169 powder on the forging matrix layer by layer to prepare mechanical property samples and metallographic samples.Along the direction of stress loading,half of the laser-repaired samples were GH4169 forgings and the other half were laser-deposited GH4169 alloy.At the same time,mechanical properties of the base material GH4169 forgings were prepared according to the specifications for comparison.The tensile properties of repaired samples and base material at room temperature and high temperature,also fatigue properties were tested.The results and the material standard were compared and the microstructure was analyzed.The results showed that the heat affected zone was very narrow,the width was only 0.1~0.2 mm,the metallurgical quality of the cladding zone was good,no obvious cavities and fusion defects were found.The tensile strength of the repaired samples reached 1299 MPa at room temperature and 1069 MPa at high temperature,which were equivalent to the base material,and higher than the material standard;plasticity reduced to 50%of base metal.The fatigue properties of the transverse samples were higher than that of the base metal,and the fatigue properties of the longitudinal samples were lower,but they belonged to the same order of magnitude.After repairing,the part had small deformation,the axial size change at the assembly was no more than 0.05 mm,the run out change of the outer circle was no more than 0.02 mm,which could ensure the dimensional accuracy of parts.After X-ray non-destructive test,there were no pores larger than 0.3 mm,no aggregation defects,no cracks,etc.inside the part,the repaired part reached the corresponding acceptance criteria.It was verified by the installed test that it was suitable for the repairing of aviation components under static load and at temperatures lower than 500℃.This method was effective for rapid and precise repairing of aviation parts.Generally,laser repaired area needed heat treatment,but in some cases,such as the precision parts with the non-main bearing at a certain temperature,there was no heat treatment conditions.The test defined the scope of parts which did not need to do heat treatment,and had a certain engineering application value.
作者
刘雪丽
李和智
卿颖
杨春蓉
王忠
Liu Xueli;Li Hezhi;Qing Ying;Yang Chunrong;Wang Zhong(Aero Engine Corporation of China Aero Science and Technology Co.,Ltd.,Chengdu 610503,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2021年第6期758-762,共5页
Chinese Journal of Rare Metals
基金
四川省重点研发项目(2018G20075)资助。
