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激光冲击强化(LSP)是一项新的表面强化处理技术。阐述了LSP技术表面强化的工艺优点和应用领域;介绍了国内外激光强化技术、工艺及设备研究和实际应用情况;分析了该技术在应用推广中亟待解决的设备研制、工艺改进等关键问题,并对其未来的应用前景、发展方向做了展望。 相似文献
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喷丸强化技术在我国的发展 总被引:2,自引:0,他引:2
本文简要地介绍了国外喷丸强化技术的发展,主要综述了国内喷丸强化技术的发展过程及它在工业部门中的应用情况,讲述了该强化技术在改善机械产品疲劳强度、提高产品可靠性中的作用。 相似文献
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本文介绍了激光冲击强化技术这种新型的金属材料表面强化技术,该技术可大幅度提高金属材料的疲劳寿命,为提高传统材料的综合力学性能和服役行为开辟了新路;文章重点论述了该技术在美国的工程应用情况以及国内的研究进展,最后简述了我国首条激光冲击强化生产线相关情况。 相似文献
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相变储热技术能够解决热能传递过程中的时空不连续问题,可有效减少热能的损耗,加速中国碳中和目标实现进程。但受限于相变材料的低导热特性,实际应用中的相变储热系统均需配置相应的传热强化装置,使系统复杂性和投资成本大幅增加。本文对相变储热技术的传热强化方法进行了简要分类,即单一传热强化技术、组合传热强化技术、多级传热强化技术以及液态PCM流动强化技术,并对后三者的不足进行阐述和说明。同时,基于相应结论,归纳总结了热源与热汇的三种相对几何关系,即扩张式、平行式和收缩式,可有效指导相变储热器结构总体设计。最后,对相变储热技术的未来应用进行了展望,应基于热力学和系统论等知识,从系统层面完成相变储热器的设计,实现热力学性能和经济性的最优。 相似文献
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Laser peening and shot peening effects on fatigue life and surface roughness of friction stir welded 7075-T7351 aluminum 总被引:1,自引:0,他引:1
OMAR HATAMLEH JED LYONS ROYCE FORMAN 《Fatigue & Fracture of Engineering Materials & Structures》2007,30(2):115-130
The effects of laser peening, shot peening, and a combination of both on the fatigue life of Friction Stir Welds (FSW) was investigated. The fatigue samples consisted of dog bone specimens and the loading was applied in a direction perpendicular to the weld direction. Several laser peening (LP) conditions with different intensities, durations, and peening orders were tested in order to obtain the optimum peening parameters. The surface roughness resulting from various peening techniques was assessed and characterized. The results indicate a significant increase in fatigue life using LP compared to shot peening when tested on their native welded specimens. 相似文献
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H. Ishigami K. Matsui Y. Jin & K. Ando 《Fatigue & Fracture of Engineering Materials & Structures》2000,23(11):959-963
The technique of shot peening is commonly used to increase the fatigue limit of a steel. However, there are many practical difficulties in applying it to very high HV steel and complicated components. To overcome these problems, the authors proposed two new methods: stress double shot peening and stress reflection double shot peening. Both techniques were applied to quench and tempered steel (QT steel) and induction-heated steel (IH steel). The main results were as follows: (a) by double shot peening, the compressive residual stress near the sample surface was increased considerably; (b) by stress shot peening, the maximum compressive residual stress ( σ max ) and the surface compressive residual stress ( σ s ) were greatly increased; (c) by stress double shot peening, very high compressive residual stresses ( σ max = −1710 MPa and σ s = −1320 MPa) were successfully introduced into a hard steel (HV = 700); (d) in the new method (stress reflection double shot peening), very high compressive residual stresses ( σ max = −1760 MPa and σ s = −1460 MPa) were successfully introduced into a hard steel (HV = 700). 相似文献
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首先对等轴状TC4钛合金疲劳试样表面进行了不同时间的高能喷丸,制备出一定深度的纳米表层,然后采用小尺寸弹丸进行表面损伤修复喷丸,提高纳米表层质量,最后对不同喷丸状态的试样进行了疲劳试验。结果表明:复合喷丸使等轴状TC4钛合金的疲劳强度相比未喷丸状态提高了34%,在单纯高能喷丸纳米化方法的基础上进一步提高了12%;高能喷丸在试样表面形成的损伤阻碍了表层纳米化提高疲劳强度的效果,通过修复喷丸可以修复部分高能喷丸损伤。 相似文献
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针对薄壁主动齿轮失效原因,提出了提高薄壁主动齿轮性能的工艺改进方案,即从强力喷丸,提高齿根粗糙度,改进组装工艺以降低齿根拉应力,从而提高齿轮的疲劳强度和运行寿命. 相似文献
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Effects of peening on mechanical properties in friction stir welded 2195 aluminum alloy joints 总被引:2,自引:0,他引:2
The effects of surface treatment techniques like laser and shot peening on the mechanical properties were investigated for friction stir welded 2195 aluminum alloy joints. The loading in the tensile specimens was applied in a direction perpendicular to the weld direction. The peening effects on the local mechanical properties through the different regions of the weld were characterized using a digital image correlation technique assuming an iso-stress condition. This assumption implies that the stress is uniform over the cross-section and is equal to the average stress. The surface strain and average stress were used giving an average stress–strain curve over the region of interest. The extension of the iso-stress assumption to calculate local stress–strain curves in surface treated regions is a novel approach and will help to understand and improve the local behavior at various regions across the weld resulting in a sound welding process. The surface and through-thickness residual stresses were also assessed using the X-ray diffraction and the contour methods. The laser peened samples displayed approximately 60% increase in the yield strength of the material. In contrast, shot peening exhibited only modest improvement to the tensile properties when compared to the unpeened FSW specimens. The result that laser peening is superior to shot peening because of the depth of penetration is original since this superiority has not been presented before regarding mechanical properties performance. 相似文献
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Influence of shot peening parameters on high‐cycle fatigue strength of steel produced by powder metallurgy process
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H. K. Akyıldız M. K. Kulekci U. Esme 《Fatigue & Fracture of Engineering Materials & Structures》2015,38(10):1246-1254
In this study, the effect of shot peening parameters on fatigue strength of steel manufactured by powder metallurgy (PM) was investigated. Steel material obtained from Höganas ASC 100.29 in chemical composition of Fe–0.5% C–2% Cu was produced by using a single action press PM process. To determine the effect of shot peening parameters on fatigue performance, fatigue tests were performed on 20 unpeened and 80 shot‐peened samples, which were machined from sintered steel. Furthermore, shot‐peened samples were peened at different peening intensities, 100% and 200% saturation and full coverage conditions. Fatigue performance of steel, produced by PM process, was improved by surface peening process. For the studied PM steel, the best fatigue performance was obtained with the samples that were shot peened at 20 Almen intensity and 100% saturation. Fatigue strength and limit of the samples, however, were reduced after a certain cold work level. Higher intensity and saturation levels of peening process thus deteriorated the beneficial effect on fatigue strength and limit. 相似文献
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Turnbull De Los Rios Tait Laurant & Boabaid 《Fatigue & Fracture of Engineering Materials & Structures》1998,21(12):1513-1524
Four-point bending fatigue tests were conducted to study the effect of shot peening on the fatigue life of the nickel-base superalloy, Waspaloy. The influence of shot peening intensity on crack initiation, Stage I crack growth and the Stage I-to-Stage II crack growth transition phases, has been examined to identify the mechanisms by which shot peening improves fatigue resistance. The potential for extending the fatigue life of fatigue-damaged Waspaloy components has been explored by shot peening specimens which had been cyclic damaged to various degrees. The fatigue test was then continued after peening to ascertain the possibility of crack arrest or extending fatigue life. These experiments explore the possibility of 'healing' fatigue damage by a surface engineering treatment. 相似文献
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目的 以喷丸成形工艺下的2024-T351铝合金平板件和单筋件为研究对象,分析弦向及展向曲率半径试验值与拟合值的变形规律。方法 针对试件厚度、喷丸压力、喷丸速度、预弯量4个参数进行喷丸成形操作的正交试验,通过测量成形后曲率的变化规律,分析不同参数组合对平板件和单筋件成形变化规律的影响。结果 在不考虑材料性能波动的情况下,随着平板件厚度和喷丸速度的增大,平板试件的弦向曲率半径和展向曲率半径均呈递增趋势;而随着喷丸压力的增大,平板试件的弦向曲率半径和展向曲率半径则呈现递减趋势,即当平板件厚度和喷丸速度增大时,喷丸成形对平板试件弯曲的影响程度有所增大,曲率半径减小;反之,喷丸成形对平板试验件弯曲的影响程度减小,曲率半径增大。结论 在忽略初始状态并将其假设为自由状态或给定预弯量状态的条件下,随着喷丸速度的增大,单筋试件的曲率半径递增,试验值与拟合值的变化趋势基本相符,二者最大偏差为11.2%。 相似文献
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Koji Takahashi Yuta Kogishi Norihito Shibuya Fumiaki Kumeno 《Fatigue & Fracture of Engineering Materials & Structures》2020,43(4):845-856
The effects of laser peening (LP) on the bending fatigue strength of the 7075‐T651 aluminum alloy were investigated. Accordingly, the defect tolerance of the aluminum alloy subjected to LP is discussed on the basis of fracture mechanics. The results indicate that a deeper compressive residual stress was induced by LP compared with the case of shot peening (SP). The fatigue strengths increased when both peening types were used. Semicircular slits with depths less than 0.4 and 0.1 mm were rendered harmless on the basis of the applications of LP and SP, respectively. The apparent threshold stress intensity factor range ΔKth,ap increased by approximately five and two times owing to LP and SP, respectively. The increase of the ΔKth,ap was caused by the compressive residual stress induced by the peening. The Kitagawa‐Takahashi diagram of the laser‐peened specimens shows that the defect tolerance of the aluminum alloy was improved by LP. 相似文献