低温微量润滑技术及其作用机理研究

随着高效绿色切削技术的发展,低温微量润滑技术应运而生。它是在微量润滑的基础上结合低温冷风发展而来。文中简要介绍了低温微量润滑技术及其切削性能。低温微量润滑技术体现了良好的切削性能,大大提高了刀具耐用度,为以后更好的应用奠定了坚实的基础。同时,文中还阐述和分析了低温微量润滑的渗透机理,以及冷却和润滑作用机理。通过理论分析,低温微量润滑技术能够更有效地实现对切削加工区的冷却和润滑。并通过试验证明,低温冷风结合微量润滑技术能够有效地降低切削温度和切削力,改善切削加工性能。     

纳米流体微量润滑在高效铣削加工中的应用前景分析

高效铣削广泛应用于模具型腔加工中,为保护环境实现绿色制造,生产上冷却润滑方式已逐步从浇注式、干式、低温冷却、微量润滑等方向发展。分析了传统浇注式铣削、干式铣削、低温冷却铣削、微量润滑铣削的技术特征与瓶颈。借鉴纳米粒子具有更强的冷却性能和优异摩擦学特性而发展的纳米流体微量润滑高效铣削加工工艺,有望解决目前高效铣削加工环保压力与换热能力不足的技术瓶颈。分析了纳米流体微量润滑铣削的国内外研究现状,提出了纳米流体微量润滑高效铣削加工中的科学问题与关键技术,展望了纳米流体微量高效铣削的应用前景与发展趋势。     

低温微量润滑加工技术研究进展与应用

综述了低温微量润滑技术的最新进展,阐明了研究成果中的关键科学问题.首先,系统分析了从传统设置到创新设计的低温微量润滑装备在切削中的应用形式和工艺特点.其次,揭示了低温微量润滑的冷却润滑机理及其对切削热力演变和工件表面质量的影响机制.然后,基于低温微量润滑的作用机理和应用形式,系统分析了低温微量润滑在车削、铣削、磨削中针...     

微量润滑复合增效技术及其应用研究进展

微量润滑技术具有切削液用量少、润滑效率高等优点,但在特定工况下仍存在冷却性不足以及润滑不充分等问题.微量润滑复合增效技术,如低温冷风、液态CO2等,综合了良好冷却和润滑优势,可有效解决难加工材料清洁切削加工难题.综述了各类微量润滑复合增效技术原理、关键装置及其工艺应用最新研究进展,详细剖析了各类装置性能及其参数调控特性...     

低温微量润滑切削技术及其应用

针对传统的大浇注式切削加工存在切削液浪费大、冷却润滑效果不好、成本高、污染环境、危害个人健康等问题,介绍了一种新的润滑冷却方式,即低温微量润滑(MQL)技术.通过微观角度研究传统浇注式和MQL切削加工中切削液的作用机理和相关的实验结果,对比发现低温微量润滑技术在实际应用中具有很多方面的优势,这项技术具有较高的推广价值和广阔的应用前景,比较符合绿色可持续发展之路.     

不同冷却工况下的磨削钛合金温度场模型及验证

为克服普通纳米流体微量润滑在磨削区换热能力不足的技术瓶颈,提出了低温风冷+纳米流体微量润滑的新工艺,并建立了温度场有限差分模型。对低温风冷+纳米流体微量润滑、低温风冷、纳米流体微量润滑三种冷却方式下的磨削温度场进行了数值仿真,结果表明低温风冷+纳米流体微量润滑的换热能力最强,低温风冷次之,纳米流体微量润滑最弱。在三种不同冷却方式下对钛合金Ti-6Al-4V平面磨削温度场进行了实验,工件表面最高温度相对误差小于5%,验证了理论模型的正确性。     

高速车削中低温最小量润滑方式的冷却润滑性能

基于复合制冷技术研制一种低温最小量润滑供给装置,分析低温最小量润滑切削的冷却润滑作用,通过干切削、常温冷风、最小量润滑(Minimum quantity lubrication,MQL)、低温冷风、低温最小量润滑(低温MQL)5种冷却润滑条件下高速车削钛合金的切削温度、切削力对比试验,研究低温MQL在高速车削中的冷却润滑性能。结果表明,5种冷却润滑条件中,低温MQL能够最有效降低切削温度,且随着切削速度的提高,其降低切削温度的效果更明显;低温MQL优异的冷却效果有益于微量润滑油润滑作用的发挥,使其对切削区的润滑效果优于MQL,有效地降低高速车削钛合金时的切削力,改善刀具前刀面摩擦状况。     

绿色切削微量润滑增效技术研究进展

微量润滑技术作为一种绿色高效的加工方法,具有切削液用量少、切削力低、防止黏结、延长刀具寿命、提高工件表面质量等优点。但在特定工况下单独使用微量润滑技术又存在润滑不充分、冷却性能不足等问题,为此专家学者提出了若干种微量润滑增效技术。综述了微量润滑增效技术的原理、实施方案和工艺应用的最新研究进展,旨在扩展微量润滑技术的应用范围,也为微量润滑增效技术的进一步研究提供理论支撑和科学指导。     

绿色磨削加工技术研究现状及进展

传统的磨削加工大量采用磨削液浇注法降低加工区温度,磨削液的大量使用给环境和操作者健康带来了很大危害,而且增加了磨削液排放回收的成本.本文分析了绿色磨削加工技术,如干磨削技术、微量润滑、液氮冷却、低温气体冷却、高压射流冷却、内冷却和固体润滑冷却技术在机械制造中的应用及其技术特征.绿色磨削加工技术将逐渐取代传统的浇注供液方...     

低温冷却GH4169高温合金插铣刀具磨损试验研究

针对GH4169高温合金高效插铣工艺,研究了不同冷却方式对插铣刀具寿命的影响。设计CO2低温微量润滑冷却系统,进行了CO2低温微量润滑冷却插铣刀具磨损切削试验,并与其他冷却方式进行对比。从磨损曲线、磨损影像及磨损率3个角度对刀具磨损量、刀具刃口磨损形貌及磨损速度进行了分析。试验结果表明,CO2低温微量润滑冷却对提高刀具耐用度有显著影响,有助于减缓刀具磨损,改善切削环境。可以通过改变冷却条件方式提升GH4169高温合金插铣刀具使用寿命。     

Cryogenic minimum quantity lubrication machining: from mechanism to application

Cutting fluid plays a cooling–lubrication role in the cutting of metal materials. However, the substantial usage of cutting fluid in traditional flood machining seriously pollutes the environment and threatens the health of workers. Environmental machining technologies, such as dry cutting, minimum quantity lubrication (MQL), and cryogenic cooling technology, have been used as substitute for flood machining. However, the insufficient cooling capacity of MQL with normal-temperature compressed gas and the lack of lubricating performance of cryogenic cooling technology limit their industrial application. The technical bottleneck of mechanical–thermal damage of difficult-to-cut materials in aerospace and other fields can be solved by combining cryogenic medium and MQL. The latest progress of cryogenic minimum quantity lubrication (CMQL) technology is reviewed in this paper, and the key scientific issues in the research achievements of CMQL are clarified. First, the application forms and process characteristics of CMQL devices in turning, milling, and grinding are systematically summarized from traditional settings to innovative design. Second, the cooling–lubrication mechanism of CMQL and its influence mechanism on material hardness, cutting force, tool wear, and workpiece surface quality in cutting are extensively revealed. The effects of CMQL are systematically analyzed based on its mechanism and application form. Results show that the application effect of CMQL is better than that of cryogenic technology or MQL alone. Finally, the prospect, which provides basis and support for engineering application and development of CMQL technology, is introduced considering the limitations of CMQL.     

MQL加工的微量冷却润滑系统

针对大量浇注式传统切削冷却润滑存在的主要问题，提出并构建了由供液系统、切削液和雾液回收装置所组成的适用于MQL加工的微量切削液冷却润滑系统，并阐述了微量冷却润滑系统对机床、工具系统和刀具兼容性的要求，为制造微量切削液冷却润滑系统和实施MQL加工工艺提供了理论和工程依据。     

最小量润滑在振动钻削中的应用

为了有效地发挥最小量润滑(Minimum quantity lubrication,MQL)在钻削加工中的冷却和润滑性能,把MQL和振动钻削技术结合起来,对MQL在钻削加工(尤其是振动钻削)中的作用效果进行理论分析和试验研究,并对加工中的最大轴向力和表面粗糙度进行测量.研究结果表明,与普通钻削相比,振动钻削能够有效改善MQL的作用效果,通过合理选择参数,能使最大轴向力明显减小,表面粗糙度显著改善;增大振幅是提高MQL作用效果的有效途径,能够降低表面粗糙度,提高加工质量.     

基于微量润滑的切削油雾雾化特性测试与分析

微量润滑切削时,切削油雾的粒径分布与浓度等是衡量切削环境空气质量必不可少的特征变量,同时也是揭示微量润滑切削机理的重要参数.本文基于光衍射原理对油雾颗粒的体积分布等进行测量,深入分析了微量润滑条件下切削油雾的雾化特性,揭示了微量润滑系统各参数如润滑油用量、供气压力、喷射靶距及润滑油黏度等对油雾颗粒体积分布的影响规律,为...     

Experimental Investigation on the Compatibility of Nanoparticles with Vegetable Oils for Nanofluid Minimum Quantity Lubrication Machining

Several health and environmental related issues caused by the application of traditional cutting fluids in machining can be solved by implementing eco-friendly technologies such as minimum quantity lubrication (MQL). Moreover, nanofluid MQL has been proposed to enhance the cooling/lubricating properties of pure MQL and displays significantly good results for machinability. However, the mechanism on compatibility of nanoparticles with cutting fluids has not been explored. In this study, nanoparticles with different hardness and vegetable oils with different viscosity were selected for nanofluids preparation. The end milling experiments were carried out on 7050 material by applying MQL with particularly prepared nanofluids. The cutting force and surface roughness were measured corresponding to the machining performance. The compatibility of hardness of nanoparticles with viscosity of base fluids has been evaluated, and the mechanism has been analyzed by new-designed tribology tests. Results show that canola oil-based diamond nanofluids MQL exhibit the lowest cutting force and natural77 oil-based diamond nanofluids perform the lowest surface roughness with reduction of 10.71 and 14.92%, respectively, compared to dry machining condition. The research is novel and contributes to the machining of such materials at the industry level.     

Investigation into the performance of eco-friendly graphite nanofluid as lubricant in MQL grinding

In this study, the lubrication and cooling properties of eco-friendly graphite nanofluids in MQL grinding were investigated. Grinding forces, subsurface temperature of workpiece, surface roughness, micro-hardness and metallographic observations of ground surfaces were employed to evaluate the performance of synthesized nanofluids as lubricant under different grinding parameters. The results were also compared with grinding in dry, pure MQL and flood cooling conditions. The results showed that the tangential forces and force ratios in grinding using graphite nanofluid MQL are lower than that of other lubricating methods especially at extreme cutting parameters. Also, application of graphite nanofluid MQL reduced the grinding temperature at high velocities of workpiece. These reductions could be attributed to the formation of a tribofilm on the ground surface by the present of graphite nanoparticles in the wheel-workpiece interface. Additionally, the presence of this tribofilm in the contact area generated a smooth surface even at high depth of cut and velocity of workpiece. Furthermore, the micro-hardness of ground surfaces increased in graphite nanofluid MQL grinding because of infiltration of graphite nanoparticles in the grinding surface and the plastic deformation of subsurface of workpiece.     

Study on minimum quantity lubrication in micro-grinding

This paper discusses the performance of the minimum quantity lubrication (MQL) in micro-grinding based on ground surface roughness and tool life. The effects of grinding and lubricating parameters on machining performance are studied. Experiments for dry grinding and grinding with pure air are also conducted for comparison. It is observed that surface roughness and tool life are improved with the application of MQL in micro-grinding. Experimental results show that efficient chip removal from the cutting zone in micro-grinding is important for achieving good surface finish and adequate tool life. The application of a small amount of cutting oil in MQL can significantly extend the tool life. In this study, the tool life in MQL is seven times longer than that in dry grinding and five times longer than that in grinding with air cooling. If the oil flow is surplus to requirements or the air flow is inadequate, excess oil will stay on the grinding tool after the grinding test. As a result, poor surface roughness is observed. The optimal lubrication conditions in this experimental exploration are the combination of an oil flow of 1.88?ml/h and an air flow of 25?L/min.     

Theoretical and experimental study of the chatter vibration in wet and MQL machining conditions in turning process

Turning is one of the most commonly used cutting processes for manufacturing components in production engineering. The turning process, in some cases, is accompanied by intense relative movements between tool and workpiece, which is called chatter vibrations. Chatter has been identified as a detrimental problem that adversely impacts surface finish, tool life, process productivity, and dimensional accuracy of the machined part. Cooling/Lubrication in the turning process is normally done for some reasons, including friction and force reduction, temperature decrement, and surface finish improvement. Wet cooling is a traditional cooling/lubrication process that has been used in machining since the past. Besides, a variety of new cooling and lubricating approaches have been developed in recent years, such as the minimum quantity lubrication (MQL), cryogenic cooling, nanolubrication, etc., due to ecological issues. Despite the importance of cooling/lubrication in machining, there is a lack of research on chatter stability in the presence of cutting fluid in cutting processes. In this study, the chatter vibration in turning process for two cooling/lubrication conditions of conventional wet and MQL is investigated. An integrated theoretical model is used to predict both the metal cutting force and the chatter stability lobe diagram (SLD) in turning process. This model involves deriving a math equation for predicting metal cutting force for both wet and MQL conditions using experimental training force data and a Genetic Expression Programming (GEP)-based regression model. Also, the traditional single degree of freedom chatter model is used here for predicting the SLDs. The chatter model is discussed and verified with experimental tests. Then, the experimental results of the tool's acceleration signal, work surface texture, surface roughness, chip shape, and tool wear are presented and compared for wet and MQL conditions. The results of this study show that the cooling/lubrication systems such as wet or MQL have a considerable effect on the SLDs. Also, the predicted results of metal cutting force and SLD for both wet and MQL techniques are in good agreement with the experimental data. Therefore, it is recommended that for each lubrication condition including wet, or MQL, the SLD be determined to achieve higher machinability.     

低温最小量润滑供给装置及其性能测试

低温最小量润滑(Cryogenic minimum quantity lubrication,低温MQL)是将低温压缩空气(通常为-10-30℃)与微量润滑油混合雾化后,喷射至加工区,对加工区实施冷却和润滑的一种准干式绿色切削技术。研制高性能低温MQL供给装置是研究和应用该项技术的前提。本文在分析低温MQL供给装置研制现状的基础上,提出采用以复合制冷方法研制一种低温MQL供给装置,并用热电偶和三维粒子动态分析仪对其制冷性能和喷雾性能分别进行了测试,为其在低温MQL切削研究中的应用奠定了基础。