摘要: |
结合航空发动机大型风扇机匣TC4钛合金静子叶片的修复需求,研究了损伤叶片的激光熔覆修复工艺,对熔覆层成分、组织、显微硬度及力学性能进行了分析。试验结果表明,激光熔覆层TC4钛合金的O、N、H元素成分满足标准要求;激光熔覆区为具有魏氏体组织特征的柱状晶,柱状晶内部为细密的马氏体组织,热影响区为柱状晶和双态组织的混合组织,并逐渐过渡到基体的双态组织;激光熔覆层显微硬度平均比母材高15%,过渡平缓;激光熔覆TC4试样的室温拉伸、400 ℃高温拉伸、热暴露试验的强度结果均高于母材试样,断后延伸率稍低。采用单道多层熔覆工艺对受损叶片进行修复,验收合格后,风扇机匣得到使用。 |
关键词: 风扇机匣 TC4钛合金 静子叶片 激光熔覆 微观组织 力学性能 修复 |
DOI:10.11933/j.issn.1007-9289.2015.06.019 |
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Repairing TC4 Titanium Stator Blade of Aero-Engine Fan Casing by Laser Cladding |
LUO Kuilin, GUO Shuangquan, HE Yong, FU Junbo
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Chengdu Holy (Group) Industrial Co., Ltd.
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Abstract: |
To repair TC4 titanium stator blades of large aeroengine fan casing, the repair process of damaged blades by laser cladding was researched, and the compositions, microstructure, microhardness and mechanical properties of the laser cladding zone were analyzed. The experimental results indicate that contents of elements such as O, N, H in the laser cladding zone comply with the standard requirements. The laser cladding zone consists of columnar grain with typical Widmanstatten structure in which fine martensite structure is distributed. The heat affected zone consists of the mixture structure of columnar grain and duplex microstructure, transiting from mixture structure to duplex microstructure as getting close to the base metal. The average microhardness of the laser cladding zone is 15% higher than that of the base metal, and the microhardness transition from the laser cladding zone to the metal base is mild. The tensile strengths by roomtemperature tensile test, elevated temperature tensile test (at 400 ℃) and thermal exposure test for laser cladding TC4 titanium sample are all higher than those for the base metal, while the elongations are slightly lower. The damaged stator blades are repaired by singlepath and multilayer laser cladding method. The fan casing is put into use after acceptance. |
Key words: fan casing TC4 titanium stator blades laser cladding microstructure mechanical properties repair |