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.     

基于MQL的切削加工技术应用

在金属切削加工过程中,切削液发挥着冷却、润滑、排屑和防锈等作用,但其排放会对环境造成严重污染。微量润滑技术(MQL)是将压缩气体与微量润滑油混合汽化后喷射到加工区域,可代替传统切削液,在刀具与工件间的加工部位形成有效润滑,减缓刀具磨损。作为新兴的绿色清洁切削加工技术,微量润滑技术具有广阔应用前景。本文介绍了切削加工机理和切削液在切削加工中的作用,通过对比微量润滑、水溶性切削液和切削油性冷却等常见润滑技术的优缺点,分析了MQL替代传统切削液在切削加工中的利弊,并通过分析MQL在高速加工、铝合金加工及断续加工等方面的应用,探讨了MQL技术的发展趋势及发展过程中凾待解决的问题。     

微量润滑方式对车削42CrMo钢断屑效果的影响分析

当前企业生产中多采用切削液辅助车削42CrMo钢，存在断屑难和环境污染重的问题，相比于切削液冷却方式，微量润滑体现出低成本、低资源消耗和洁净无毒等诸多优势，成为研究的热点。为了探究微量润滑技术是否可以替代切削液冷却方式并且获得更优的断屑效果，基于双喷头微量润滑的冷却装置，采用单独前刀面、单独后刀面和前、后刀面同时微量润滑三种冷却方式，与传统切削液辅助加工进行对比，分析冷却方式对车刀断屑效果的影响，并结合切削力与加工表面形貌确定最优冷却方式。试验结果表明，前、后刀面同时微量润滑的方式效果最优，相比传统切削液冷却方式，前、后刀面同时微量润滑的方式所获得的切屑长度可缩短35.9%,切削合力降低14.7%,加工表面粗糙度降低34.7%。因此在车削42CrMo钢时，微量润滑技术在设备空间允许的条件下可考虑作为一种更高效洁净的冷却润滑手段。     

微量油膜附水滴切削试验研究

论述微量油膜附水滴(Oil on Water,OoW)加工液发生原理和冷却润滑特点.针对该切削液的冷却润滑特点进行车削试验研究,并在同干切削和乳化液冷却润滑加工方式对比研究的基础上,通过对切削力、平均摩擦因数和切屑形态的研究分析,揭示出微量油膜附水滴具有良好的冷却润滑效果.     

微量润滑技术作用机理研究

基于生态及环保的需求,切削加工中的绿色制造技术及微量润滑(MQL)技术成为当今研究的焦点.依据实验结果及微量润滑技术的研究现状,分析了微量润滑技术的具体优势,探讨了微量润滑(MQL)技术的渗透机理、冷却机理及切削机理.     

微量油膜附水滴不同喷射方向切削效果试验研究

利用油膜附水滴(OoW)切削液进行切削试验研究,并采用不同喷射角度进行喷射冷却润滑.试验结果表明,同干切削、乳化液冷却润滑加工相比,微量油膜附水滴能够降低切削力的产生,对后刀面和刀具侧面进行喷射切削效果更好;微量油膜附水滴切削液能够显著降低加工表面的粗糙度.     

低温微量润滑切削304不锈钢的实验研究

低温MQL切削是低温冷风与微量润滑（MQL）相结合的一种绿色环保加工技术。采用改造的YT15刀具对304不锈钢进行低温MQL切削实验,并比较干切削、湿切削、低温MQL切削三种方式对工件的表面粗糙度以及切屑形态的影响。结果表明,低温MQL采用高压低温冷风冷却润滑,高压冷风可直接将润滑油带入刀-屑和刀-工件接触区域,起到更好的润滑作用,有效降低切削区的温度;相对干切削和湿切削,低温MQL切削能明显降低表面粗糙度,改善其断屑性能,获得较好的切屑形态。     

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.     

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。     

微量润滑技术切削7075铝合金试验研究

采用传统切削液冷却方式加工7075铝合金时,工件表面粗糙度较高,表面质量差,资源消耗大。针对上述问题,通过对采用微量润滑切削加工7075铝合金的研究,设计了微量润滑冷却与切削液冷却的对比试验。试验结果表明,增加微量润滑喷雾油量可以在一定程度上降低工件表面粗糙度,随着喷雾油量的增加,其对工件表面粗糙度的影响减小,最终趋向平稳状态。当切削速度为200～400 m/min时,使用2种润滑方式得到的工件表面粗糙度随着速度的增加而变小;当切削速度从200～400 m/min继续增大时,采用微量润滑冷却方式得到的工件表面粗糙度随着切削速度的增加而增大,在600 m/min的切削速度时最为明显。微量润滑相比于传统切削液冷却具有更好的润滑性能,可以减少因为切削过程中润滑不良而产生的表面不良缺陷。     

超声波处理乳化液在金属切削中的试验研究

为了研究超声波处理对乳化液冷却润滑性能的影响,设计了用于切削试验的乳化液超声波处理系统,并在干切、未采用超声波处理乳化液和采用超声波处理乳化液三种条件下,采用YT15刀具车削45钢进行了对比试验。结果表明：使用超声波处理乳化液时,切削力可比干切和未采用超声波处理乳化液时分别减小10%~15%和5%~10%;变形系数也减小了,切屑形貌得到改善。通过测量液体粒度可知,超声波处理使乳化液的分子团粒径减小,乳化液进入切削区毛细管的可能性增大,说明超声波处理能够提高乳化液的冷却润滑作用效果,也可理解为间接地减少了乳化液的用量,有利于节能减排。     

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.     

Deformation behaviour of sintered silicon–copper steel preforms of various aspect ratios during cold upsetting

This paper presents the optimization of the face milling process of 7075 aluminum alloy by using the gray relational analysis for both cooling techniques of conventional cooling and minimum quantity lubrication (MQL), considering the performance characteristics such as surface roughness and material removal rate. Experiments were performed under different cutting conditions, such as spindle speed, feed rate, cooling technique, and cutting tool material. The cutting fluid in MQL machining was supplied to the interface of work piece and cutting tool as pulverize. An orthogonal array was used for the experimental design. Optimum machining parameters were determined by the gray relational grade obtained from the gray relational analysis.     

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.     

亚干式深孔钻削系统及其试验分析

将亚干式切削技术与深孔加工技术相结合,在BTA内排屑深孔加工系统的基础上,采用风冷雾化排屑系统代替BTA系统中的切削液排屑系统,形成亚干式深孔加工系统,从而实现风冷雾化切削液对刀具进行冷却润滑和排屑的功能,以减少切削液的使用及环境污染。并在不同的切削用量条件下对亚干式深孔加工与BTA深孔加工的切削力进行了对比试验及分析。试验证明该系统在合理的切削条件下切削力和排屑情况要比BTA系统具有优越性。     

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.     

低温氮气射流对钛合金高速铣削加工性能的影响

在钛合金的高速切削过程中，切削区温度很高，加速了刀具的磨损，限制了切削速度的进一步提高。为降低切削区温度、防止刀具的氧化磨损，提出在低温氮气射流条件下进行钛合金的高速铣削加工。在干铣削、浇注切削液、常温氮气油雾、低温氮气射流和低温氮气射流结合微量润滑等冷却润滑条件下进行了钛合金的高速铣削对比试验。试验结果表明，低温氮气射流结合微量润滑能够最有效地降低铣削力，抑制刀具磨损。借助扫描电镜的检测手段，研究了不同冷却润滑条件下刀具的失效形式。指出在低温氮气射流条件下高速铣削钛合金时，只要热裂纹的形成与扩展未引起刀具的崩刃及刀面的剥落，进一步降低低温氮气的温度将提高刀具的使用寿命。     

新型切削液工艺试验及推广应用

不同的冷却润滑材料在金属切削及加工的过程中冷却效果亦不同。为提高切削效率、工件的精度和降低工件表面粗糙度、延长刀具使用寿命,以达到最佳的经济效果,就必须减少刀具与工件、刀具与切屑之间的磨擦,并及时带走切削区内的废料。从企业实践中探讨分析了当代新型切削液在功能方面的优势及应用。     

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.     

绿色切削加工技术分析

21世纪的制造业实施绿色制造已势在必行，绿色切削加工技术的研究应运而生。干切削技术避免了切削液的副作用，但它对刀具提出更高的要求；切削液最少量润滑技术能够使切削工作处在最佳状态下，切削液的使用量达到最少，但绿色切削液需深入研究。笔者认为，实现绿色切削加工的关键技术是：1）开发刀具技术。包括新型刀具材料和刀具涂层技术的研究和应用，优化刀具形状及结构；2）开发绿色切削液技术，包括切削液的绿色设计与绿色使用，开发切实可行的废液处理新工艺。