服役温度影响的DD6单晶高温合金磨削/喷丸加工表面完整性演化规律研究  

Study on the Evolution of Surface Integrity of DD6 Single Crystal Super Alloy by Grinding Shot Peening Based on the Effect of Service Temperature

作　　者：何喆 黄新春 宋艺辉 史耀耀[1,2] 张兆顷 史恺宁[1,2] HE Zhe;HUANG Xinchun;SONG Yihui;SHI Yaoyao;ZHANG Zhaoqing;SHI Kaining(Key Laboratory of High Performance Manufacturing for Aero Engine(Ministry of Industry and Information Technology),Northwestern Polytechnical University,Xi’an 710072;Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Ministry of Education),Northwestern Polytechnical University,Xi’an 710072;Office of Science and Technology,Northwestern Polytechnical University,Xi’an 710072)

机构地区：[1]西北工业大学航空发动机高性能制造工业和信息化部重点实验室,西安710072 [2]西北工业大学航空发动机先进制造技术教育部工程研究中心,西安710072 [3]西北工业大学科学技术研究院,西安710072

出　　处：《机械工程学报》2024年第9期410-420,共11页Journal of Mechanical Engineering

基　　金：国家科技重大专项(2017-VII-0002-0095);中央高校基本科研业务费专项资金(HYGJZN202319)资助项目。

摘　　要：DD6单晶高温合金因具备优异的耐高温性和抗蠕变性,是航空发动机涡轮叶片的重要材料。喷丸是高温合金表面强化的重要工艺,可有效去除加工刀痕,提高材料表层组织硬度,改善材料疲劳性能。为改善DD6磨削、喷丸强化后的表面完整性状态,提高工件服役性能,通过温度载荷影响实验研究,探究服役温度对DD6磨削、喷丸表面状态的影响规律。研究发现随温度升高,因表面材料产生重熔现象,导致表面形貌一致性下降,表面粗糙度增大,表层微观组织再结晶层变厚,其中表面形貌和微观组织变化受温度影响较为显著,且在喷丸强化后更为明显。采用SEM分析和EDS分析的方法对不同温度下的表面形貌和微观组织进行分析,确定影响表面形貌和粗糙度的因素主要为表面氧化现象和表层组织再结晶现象。通过分析发现表面氧化会造成表面元素流失,而表层微观组织再结晶会产生再结晶晶界,导致表层材料改性。故在加工时应考虑温度对材料表面完整性的影响合理控制磨削、喷丸工艺参数,降低微观组织损伤。研究成果为镍基单晶高温合金抗疲劳制造提供了理论依据。DD6 single crystal super alloy is an important material for turbine blades of aero engines because of its excellent high temperature resistance and creep resistance.Shot peening is an important process for surface strengthening of super alloys,which can effectively remove machining tool marks,increase the surface tissue hardness and improve the fatigue properties of the material.To improve the surface integrity of DD6 after grinding and shot peening,an experimental study on the effect of temperature loading is carried out.The influence law of service temperature on the surface condition of DD6 grinding and shot peening is investigated.It is found that with the increase of temperature,the surface material remelting phenomenon,resulting in the reduction of surface morphology consistency,surface roughness increases,the surface microstructure recrystallization layer thickened.The surface morphology and microstructure changes are significantly affected by temperature,and are more obvious after shot peening.The surface morphology and microstructure at different temperatures are analyzed by SEM and EDS.It was determined that the factors affecting the surface morphology and roughness are mainly surface oxidation phenomenon and surface tissue recrystallization.Surface oxidation is found to cause loss of surface elements and recrystallization of the surface microstructure results in recrystallized grain boundaries,leading to modification of the surface material.Therefore,the influence of temperature on the surface integrity of the material should be considered during processing,and then the grinding and shot peening process parameters should be reasonably controlled to reduce microstructure damage.The research results provide a theoretical basis for the fatigue-resistant fabrication of nickel-based single-crystal super alloys.

关 键 词：DD6 服役温度 表面完整性 磨削-喷丸 演化规律 

分 类 号：V263[航空宇航科学与技术—航空宇航制造工程]