共查询到20条相似文献,搜索用时 31 毫秒
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Xin CUI Changhe LI Wenfeng DING Yun CHEN Cong MAO Xuefeng XU Bo LIU Dazhong WANG Hao Nan LI Yanbin ZHANG Zafar SAID Sujan DEBNATH Muhammad JAMIL Hafiz Muhammad ALI Shubham SHARMA 《中国航空学报》2022,35(11):85-112
It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL) technology. Nevertheless, for aeronautical difficult-tomachine materials, MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining. Nano-biolubricants, especially non-toxic carbon group nano-enhancers(CGNs) are used, can solve this technical bottleneck. However, the machining mechanisms under lubrication of CGNs are uncl... 相似文献
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Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication(MQL), and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The specific grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were significantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%,respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%,and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS2, carbon nanotube(CNT), and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore,the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume concentrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used.Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased.Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration. 相似文献
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GH4169 alloy is one of the most commonly used materials in aero engine turbine blades, but its machinability is poor because of its excellent strength at high temperatures. Electrochemical machining (ECM) has become a common method for machining this alloy and other difficult-to-machine materials. Electrochemical grinding (ECG) is a hybrid process combining ECM and conventional grinding. In this paper, investigations conducted on inner-jet ECG of GH4169 alloy are described. Two types of inner-jet ECG grinding wheels were used to machine a flat bottom surface. The machining process was simulated using COMSOL software, and machining gaps under different machining parameters were obtained. In addition, maximum feed rates and maximum material removal rates under different machining parameters were studied experimentally. The maximum sizes and the uniformity of the distributions of the gaps machined by the two grinding wheels were compared. The effects of different applied voltages on the machining results were also investigated. 相似文献
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The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl- shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200℃, which means the developed grinding wheel makes cooling high efficient and low energy consuming. 相似文献
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Vegetable oil can be used as a base oil in minimal quantity of lubrication(MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force,and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that(1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient;(2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient;(3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil;(4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils;(5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature;(6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and(7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force,87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7% energy ratio coefficient. 相似文献
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Mingzheng LIU Changhe LI Yanbin ZHANG Min YANG Teng GAO Xin CUI Xiaoming WANG Wenhao XU Zongming ZHOU Bo LIU Zafar SAID Runze LI Shubham SHARMA 《中国航空学报》2023,36(7):160-193
Too high grinding force will lead to a large increase in specific grinding energy, resulting in high temperature in grinding zone, especially for the aerospace difficult cutting metal materials,seriously affecting the surface quality and accuracy. At present, the theoretical models of grinding force are mostly based on the assumption of uniform or simplified morphological characteristics of grains, which is inconsistent with the actual grains. Especially for non-engineering grinding wheel,most g... 相似文献
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《中国航空学报》2023,36(7):129-146
In the quest for decreasing fuel consumption and resulting gas emissions in the aeronautic sector, lightweight materials such as Carbon Fiber Reinforced Polymers (CFRPs) and Ti-6Al-4V alloys are being used. These materials, with excellent weight-to-strength ratios, are widely used for structural applications in aircraft manufacturing. To date, several studies have been published showing that the use of metalworking fluids (MWFs), special tool geometries, or advanced machining techniques is required to ensure a surface quality that meets aerospace component standards. Conventional MWFs pose a number of environmental and worker health hazards and also degrade the mechanical properties of CFRPs due to water absorption in the composite. Therefore, a transition to more environmentally friendly cooling/lubrication techniques that prevent moisture problems in the composite is needed. This research shows that lubricated LCO2 is a viable option to improve the quality of drilled CFRP and titanium aerospace components compared to dry machining, while maintaining clean work areas. The results show that the best combination of tool geometry and cooling conditions for machining both materials is drilling with Brad point drills and lubricated LCO2. Drilling under these conditions resulted in a 90 % improvement in fiber pull-out volume compared to dry machined CFRP holes. In addition, a 33 % reduction in burr height and a 15 % improvement in surface roughness were observed compared to dry drilling of titanium. 相似文献
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《中国航空学报》2021,34(5):404-414
Fiber-reinforced silica ceramic matrix composites (SiO2f/SiO2) have gained extensive attention in recent years for its applications in aeronautics field such as radar radome and window. However, the machining properties and mechanism of the material remain unclear. The features and mechanical properties of the material itself have a significant influence on both its machining characteristics and surface integrity. Thus, a full-factor grinding experiment is conducted using a 3D orthogonal SiO2f/SiO2 aiming to obtain its machining characteristics. The effects of grinding parameters and tools on the grinding force, surface roughness, and material damage type are investigated using a dynamometer, Scanning Electron Microscope (SEM), and Acoustic Emission (AE) analysis. The AE frequency band is analyzed, and a semi-analytical force model is established to study the difference between a single grain and wheel grinding. It was found that the changes in surface roughness correlate with the changes in grinding force, with fiber fracture being the main reason behind the increase in grinding force. Finally, the material removal mechanism was studied based on the AE analysis. It was found that the removal mechanism is fiber fracture dominated with matrix crack and debonding, and the primary sources of energy consumption are fiber fracture and friction. 相似文献
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针对碳纤维增强复合材料干法加工的固有缺点,提出了一种采用水溶性冷却液加工碳纤维增强复合材料的加工工艺,并对干法和湿法加工进行了对比分析。结果表明:湿法加工不影响碳纤维增强复合材料的力学性能,且能够提高加工表面质量及效率,减少刀具磨损,是碳纤维复合材料加工较好的工艺。 相似文献
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针对航空、航天、能源等国家战略领域复杂叶片高效高品质加工重大需求,对近年来以工业机器人为装备执行体的机器人磨抛加工技术的研究进展进行了综述。具体围绕叶片机器人磨抛中涉及的加工系统精确标定、测量点云高效匹配、加工轨迹自适应规划,以及柔顺力精密控制等关键工艺技术,系统而全面地分析了国内外已公开发表的相关文献,并以典型的汽轮机叶片和发动机叶片为例,阐述了叶片机器人磨抛工程应用效果。最后从叶片特殊部位一体化加工、磨抛加工颤振抑制、磨抛表面完整性控制、叶片增减材混合加工等方面对该领域未来研究方向进行了展望。 相似文献
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Suppression of Surface Burn in Grinding of Titanium Alloy TC4 Using a Self-inhaling Internal Cooling Wheel 总被引:1,自引:1,他引:1
Based on analysis of surface average temperature and burn degree, this article obtains the threshold temperature of surface burn in grinding titanium alloy with cup wheels. Meanwhile, the impact of the burn degree on the metallographic structure of workpiece surface and metallurgical phase transformations is investigated. In order to reduce the grinding temperature and improve the grinding efficiency, a self-inhaling structure cup segmented wheel is developed to generate internal cooling effect. The internal cooling technology is compared with traditional cooling conditions in the grinding experiments on TC4 (Ti-6Al-4V). The results indicate that the self-inhaling internal cooling wheel can reduce the grinding surface temperature by 30% or more, and the grinding efficiency doubles. Utilizing water-based semi-synthetic coolant, the segmented wheel with the self-inhaling structure can further reduce the grinding temperature by about 50%. 相似文献
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《中国航空学报》2021,34(4):540-567
Continuous fiber reinforced SiC ceramic matrix composites (FRCMCs-SiC) are currently the preferred material for hot section components, safety–critical components and braking components (in the aerospace, energy, transportation) with high value, and have triggered the demand for machining. However, the high brittleness, anisotropy, and heterogeneity of materials bring great challenges to machining, due to high mechanical and thermal loads, severe tool wear, and poor machining quality. With the increasing demand of FRCMCs-SiC parts, high-quality and high-efficient machining has become a hot issue. This review paper provides a detailed literature survey on the machining of FRCMCs-SiC. The material removal mechanism, defect form, and interfacial mechanical properties of FRCMCs-SiC were summarized. The machining processes of FRCMCs-SiC were introduced, and their respective advantages and disadvantages were compared. Given the low machinability (high hardness, high brittleness, anisotropy, and heterogeneity) of FRCMCs-SiC, preliminary experiments have proved that ultrasonic-assisted machining and laser-assisted machining have shown unique advantages in reducing force and tool wear, improving machining quality and machining efficiency. The machined surface integrity was discussed, the influence of process parameters on the machined surface quality was analyzed, and the machining defects of FRCMCs-SiC were summarized. But for FRCMCs-SiC, the existing quantitative evaluation of the machined surface integrity was weak and unsystematic. 相似文献
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随着航空航天、国防科技、能源等领域的快速发展,具有优良机械性能的高强度合金材料及复合材料得到广泛应用,实现这些材料的高效精密低损伤加工具有重要意义。低温等离子体富含活性粒子,能有效改善材料的可切削性,且较易产生、维持和控制,已被广泛应用于难加工材料的辅助加工过程中。在介绍低温等离子体基本特性及分类的基础上,结合国内外低温等离子体辅助加工技术的研究现状,以表面粗糙度、材料去除率、表面损伤、切削力等参数为评价指标,分别阐述了等离子体熔射成形技术、等离子体加热辅助切削技术、冷等离子体射流辅助抛光技术、冷等离子体射流辅助切削技术等的作用机理及效果,并对其发展趋势进行了展望。 相似文献
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本文介绍了固体润滑技术的润滑机理和影响因素,结合涡旋真空泵的结构特点,对固体润滑技术在涡旋真空泵的应用进行了分析研究。 相似文献
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Ultrasonic vibration-assisted grinding(UVAG) is an effective and promising method for machining of hard-to-cut materials. This article proposed an ultrasonic vibration plate device enabling the longitudinal full-wave and transverse half-wave(L2T1) vibration mode for UVAG.The characteristics of two-dimensional coupled vibration in different directions were analyzed on the basis of apparent elastic method and finite element method. Furthermore, a correction factor was applied to correct the freque... 相似文献