吴思豪,杨勇飞,施卫东,王高伟,伍祥龙,吴锐.人工淹没空化射流喷丸强化7075铝合金性能分析[J].表面技术,2024,53(7):190-199.
WU Sihao,YANG Yongfei,SHI Weidong,WANG Gaowei,WU Xianglong,WU Rui.Performance of 7075 Aluminum Alloy Strengthened by Artificially Submerged Cavitation Water Jet Peening[J].Surface Technology,2024,53(7):190-199 |
| 人工淹没空化射流喷丸强化7075铝合金性能分析 |
| Performance of 7075 Aluminum Alloy Strengthened by Artificially Submerged Cavitation Water Jet Peening |
| 投稿时间：2023-05-30 修订日期：2023-10-24 |
| DOI：10.16490/j.cnki.issn.1001-3660.2024.07.020 |
| 中文关键词: 人工淹没空化射流喷丸 7075铝合金 显微硬度 残余应力 微观结构演化 表面强化 |
| 英文关键词:artificially submerged cavitation water jet peening 7075 aluminum alloy microhardness residual stress microstructure evolution surface strengthening |
| 基金项目:江苏省自然科学基金(BK20220609);中国博士后科学基金(273746);国家自然科学基金(51979138);国家重点研发项目(2019YFB 2005300);国家高技术船舶科研计划(工信部〔2019〕360);江苏省自然科学研究项目(19KJB470029) |
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| Author | Institution |
| WU Sihao | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
| YANG Yongfei | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
| SHI Weidong | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
| WANG Gaowei | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
| WU Xianglong | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
| WU Rui | School of Mechanical Engineering, Nantong University, Jiangsu Nantong 226019, China |
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| 中文摘要: |
| 目的 利用喷丸强化技术提高材料的性能，延长零件的使用寿命。方法 在人工淹没空化射流喷丸中，利用由2个具有大速度差的同心共流射流产生的剪切层引起的空化，在承受疲劳载荷或腐蚀环境的金属部件的表面层中引入压缩残余应力，从而实现冲击性能显著提高的新型喷丸强化技术。为了进一步验证人工淹没空化射流的强化性能，采用人工淹没空化射流喷丸对7075铝合金(Al7075)进行表面强化处理，研究不同扫描速度的人工淹没空化射流喷丸对其微观组织和力学性能的影响。观测不同扫描速度人工淹没空化射流喷丸下Al7075的表面形貌和粗糙度。结果 在扫描速度为3.0 mm/min时，粗糙度值约为1.27 μm;在扫描速度为2.0 mm/min时，粗糙度值约为4.08 μm;在扫描速度为1.0 mm/min时，粗糙度值约为12.35 μm。测量了人工淹没空化射流喷丸冲击前后Al7075的残余应力和显微硬度沿深度方向的分布，研究并讨论了Al7075在人工淹没空化射流喷丸过程中的微观结构演变。结论 人工淹没空化射流喷丸会在Al7075表面发生塑性变形，增加了表面粗糙度，且产生加工硬化。揭示了Al7075在塑性变形过程中的晶粒细化机制，旨在为获得高性能的Al7075提供一种新的表面强化方法。 |
| 英文摘要: |
| Shot peening strengthening technology can be used to improve material performance and extend the service life of parts. A new type of shot peening strengthening technology has been developed which significantly improves impact performance by introducing compressive residual stress to the surface layer of metal components, thus making them more resistant to fatigue loads and corrosive environments. This is achieved through the use of cavitation caused by shear layers generated by two concentric co-flow jets with large velocity differences in artificially submerged cavitation water jet peening. In order to further verify the effectiveness of this technology, the surface strengthening treatment of 7075 aluminum alloy (Al7075) was carried out through artificial submerged cavitation water jet peening. The effects of artificial submerged cavitation water jet peening at different scanning speeds on the microstructure and mechanical properties of the alloy were studied. Samples with an inner nozzle pressure of 20 MPa, an outer nozzle pressure of 0.02 MPa, a target distance of 40 mm, and sample size of 100 mm × 100 mm × 3 mm were subject to heat treatment and polishing. The thickness of the surface hardening layer was analyzed with a TWVS-1 digital micro Vickers hardness tester, and the residual stress distribution on the surface of the impact area was measured with an X-ray stress analyzer. The surface morphology and roughness of Al7075 under artificially submerged cavitation water jet peening at different scanning speeds were also observed. The surface of the sample without impact was relatively flat, with a roughness value of approximately 0.46 μm. At the scanning speed of 3.0 mm/min, the roughness was approximately 1.27 μm. Under this working condition, the shot peening intensity was not high and the effect was poor. At the scanning speed of 2.0 mm/min, the roughness was approximately 4.08 μm, and the distribution density of the formed pits was increased; while at the scanning speed of 1.0 mm/min, the roughness increased significantly to approximately 12.35 μm due to the increased surface plastic deformation of the sample. The residual stress and microhardness distribution along the depth direction of Al7075 before and after artificially submerged cavitation jet shot peening were measured. When the scanning speed of artificially submerged cavitation jet shot peening reached 3.0 mm/min, the maximum microhardness on the surface of the sample was 118.6HV. At the speed of 2.0 mm/min, the maximum microhardness on the surface of the sample was about 125.4HV; and at the speed of 1.0 mm/min, the maximum microhardness on the surface of the sample was 124.9HV. This indicated that an effective hardening layer could be formed on the surface of Al7075 after artificially submerged cavitation jet shot peening enhancement, and the scanning speed of artificially submerged cavitation jet had little effect on the thickness of the hardening layer of the sample, which was about 600 μm. The microstructure evolution of Al7075 during artificially submerged cavitation water jet peening was studied and discussed. Firstly, the dislocation behavior lead to the formation of dislocation lines within the original coarse grains. As the strain increased, dislocation lines gradually accumulated, forming dislocation walls and dislocation entanglements. The rearrangement of dislocations formed small-angle grain boundaries, which further refined the lattice dislocation density within the grains. As the density of dislocations increased, the high-level fault energy and dislocation slip in aluminum alloys lead to dynamic recrystallization processes, resulting in increased grain boundary orientation differences. Ultimately, a gradual change in grain boundary characteristics occurred until the formation of large-angle grain boundaries. Artificially submerged cavitation water jet peening causes plastic deformation on the surface of Al7075, increasing surface roughness and producing an improved material performance, which ultimately extends the service life of the parts. |
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