Ceramic Shot-Peening of a Landing Gear Component

起落架部件的陶瓷喷丸

• 批准号: 538023-2019
• 负责人: Liu, Rong
• 金额: $ 1.82万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=680341
• 关键词: Ceramic; Shot; Peening; Landing; Gear

Shot peening is a cold working process in which the surface of a structural part is bombarded with small spherical medium called shot. The shots cause plastic deformation of the metal surface, which results in high compressive residual stresses in the area right beneath the dents. Since fatigue cracks generally originate at the surface of a part, compressive stresses induced by shot peening provide considerable increase in the part life.Landing gear flange pins are traditionally shot-peened by steel shots. However, the steel shots leave residue such as particle embedment, which could be detrimental to the service life of the pins. Also, the overall process using steel shots is lengthy. The most important is that during the high impact bombardment, the spherical shaped steel shots are plastically deformed (change the shape) and are not reusable. Therefore, the industry is trying to adopt ceramic shots that are not only reusable, but also give smoother surface finish and very low level of particle embedment/contamination.The objective of the proposed research is to investigate the possibility of replacing steel shots with harder ceramic shots. The surface quality after ceramic shot peening will be determined by measuring the roughness profile, the microstructure at the peened interface will be studied, and the residual stress will be measured from surface to the center of the specimen by XRD and stress profiles will be generated. The mechanical properties of the peened surface will be investigated via micro-indentation hardness and tensile testing, which will be compared with the unpeened specimen data.

喷丸是一种冷加工工艺，其中用称为丸粒的小球形介质轰击结构零件的表面。弹丸会导致金属表面发生塑性变形，从而在凹痕正下方的区域产生较高的残余压缩应力。由于疲劳裂纹通常起源于零件的表面，因此喷丸引起的压应力可显着延长零件的寿命。起落架凸缘销传统上采用钢丸进行喷丸处理。然而，钢丸会留下颗粒嵌入等残留物，这可能会损害销的使用寿命。而且，使用钢丸的整个过程很漫长。最重要的是，在高冲击轰击过程中，球形钢丸会发生塑性变形（改变形状），无法重复使用。因此，业界正在尝试采用不仅可重复使用，而且表面光洁度更光滑且颗粒嵌入/污染水平极低的陶瓷丸。本研究的目的是研究用更硬的陶瓷代替钢丸的可能性镜头。通过测量粗糙度轮廓来确定陶瓷喷丸后的表面质量，研究喷丸界面处的微观结构，并通过 XRD 测量样品从表面到中心的残余应力并生成应力轮廓。将通过微压痕硬度和拉伸测试来研究喷丸表面的机械性能，并将其与未喷丸样品数据进行比较。