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。     

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。     

微量润滑技术在切削加工中的应用

微量润滑(MQL)技术作为一种绿色可持续加工技术,在汽车制造、航空航天、模具制造等方面越来越受到人们的关注。介绍了传统MQL以及新型MQL(外冷复合喷雾(EOoW)、内冷复合喷雾(IOoW)和低温冷风复合喷雾(CAOoW)等)的相关原理及常见设备;MQL应用技术的关键性问题:喷雾场、油雾粒度、润滑油种类以及喷嘴位置研究情况;典型难加工材料:钛合金、复合材料、不锈钢以及铸铁MQL技术切削加工应用研究情况;MQL技术未来的研究目标。     

MQL在某大型螺旋锥齿轮机床应用的研究

大型螺旋锥齿轮应用干切式加工有一些不利的因素,所以MQL(Minimal Quantity Lubricaion)冷却润滑技术被应用到了大型螺旋锥刺轮加工中,并通过实验确定最佳润滑油量,在此基础上研究MQL冷却润滑比较干切削加工在主切削力、伺服电机功率、刀具寿命影响等方面的优越性。     

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。     

绿色切削SiCp／Al复合材料的刀具温度研究

采用嵌埋人工热电偶的方法,通过正交试验研究了干切削SiCp／Al复合材料时切削参数对刀具前、后刀面切削温度的影响。选定切削参数,实验研究了干式切削、压缩空气风冷、油液浇注和MQL等冷却方式对前、后刀面切削温度的影响。试验结果表明,对于车削SiCp／Al复合材料,后刀面温度高于前刀面温度,进给量对刀具温度影响最显著,MQL切削条件下刀具温度最低。     

基于毛细管理论的MQL理论模型及应用

MQL切削加工技术是一项新型的绿色环保加工技术,使用极微量的切削液可以取得良好的加工效果,从而达到保护环境、降低成本的目的.分析了MQL切削加工中切削液的作用原理,基于毛细管理论建立了MQL的理论模型,并进行了MQL精密车削试验,为进一步丰富和发展MQL切削技术奠定了坚实基础.     

微量润滑在GH4169高温合金车削加工中的应用

为提高GH4169高温合金的可加工性,引入了微量润滑（MQL）技术开展该材料的车削加工试验。以表面粗糙度和切削温度为性能指标,分析干切削和MQL切削条件下工艺参数对已加工表面粗糙度和切削温度的影响规律。结果表明：工件表面粗糙度值均随转速的增加而降低,随进给量的增加而增大,随背吃刀量的增加而增大;切削温度则随工件转速、进给量、背吃刀量的增加而上升;相比于干切削加工,MQL切削加工能够获得粗糙度值更小的工件表面,且切削温度更低。该研究方法对于提升GH4169高温合金产品质量和实现绿色切削具有积极的作用。     

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.     

MQL加工技术的研究与进展

最小量润滑(Minjmum Quantity Lubrication,简称MQL)是一种绿色环保切削加工技术.本文介绍了MQL加工的特点,归纳和总结了其应用研究成果,指出了MQL加工中的关键问题和尚待解决的主要问题,并探讨了其今后的发展趋势.     

Machining of sintered steel under different lubrication conditions

Cutting experiments of sintered steel Fe–2Cu–0.8C under different lubrication/cooling conditions and with different tool materials were performed in order to clarify the reasons for the low machinability of the sintered steel, and investigate the applicability of minimum quantity of lubricant (MQL) to the machining of sintered steel. As a theoretical approach to the short tool life in machining sintered steel, the impacts to the cutting edge caused by micro-voids were theoretically modeled, and it was revealed that the cutting edge suffered from impacts at a very short interval causing high cycle fatigue. Extremely short tool life in dry machining of sintered steel already used for wet machining proved that coolant definitely increased the stress amplitude in high cycle fatigue. Application of the air jet to a tool showed the positive effect in reducing tool wear. This indicated the possibility that micro-cracks nucleated by high cycle fatigue were healed by oxidation. MQL cutting with small amount of oil and air jet is proved to be acceptable for machining sintered steel from the results of cutting experiments using uncoated and coated carbide and cermet tools. Finally, it is confirmed that thick coating of a carbide tool is effective for dramatically improving the machinability.     

Investigation and optimization of lubrication parameters in high speed turning of superalloy Inconel 718

Dry machining is sometimes less effective when higher machining efficiency, better surface finish quality, and severe cutting conditions are required. For these situations, semi-dry operations utilizing very small amount of cutting fluids called minimum quantity lubrication is expected to become a powerful tool and played a significant role in a number of practical applications. It has been observed from the literature survey that a systematic research work has to be carried out to determine the optimum quantity of lubricant with appropriate cutting conditions for achieving better machinability characteristics of a material. Hence, an attempt has been made in this paper to enhance the machinability characteristics in high speed turning of superalloy Inconel 718 using quantity of lubricant, delivery pressure at the nozzle, frequency of pulses, direction of application of cutting fluid, cutting speed, and feed rate as the process parameters. Results indicated that the use of optimized minimum quantity lubrication parameters under pulsed jet mode leads to lower cutting force, cutting temperature, and flank wear.     

微量润滑油润滑和冷风冷却加工法对高硅铝合金切削面的影响

由于高硅铝合金中含有大量硅结晶粒子,硬度较大的硅结晶粒子在切削中会加速刀具的磨损,所以,其被切削性非常不好。为解决这一问题,以往是使用大量切削油进行切削加工。但是,随着环境意识的提高,大量切削油的使用所造成的环境污染的问题不得不被认识并进行改变。使用对切削点进行微量植物性润滑油润滑和冷风冷却的方法进行研究,探讨对高硅铝合金切削面的影响。并因此探讨半干式切削加工的可行性。     

Experimental evaluation on the effect of electrostatic minimum quantity lubrication (EMQL) in end milling of stainless steels

The machining of stainless steels is very challenging owing to their high toughness and low thermal conductivity, causing high cutting temperatures and rapid tool wear. Conventionally, metalworking fluids in flood form are used during the process to improve surface quality and tool life; however, their use raises issues including environmental pollution and economic concerns. Therefore, an electrostatic minimal quantity lubrication (EMQL) technology was developed to reduce the consumption of metalworking fluids. EMQL is a near-dry machining technology utilizing the synergetic effects between electrostatic spraying and minimum quantity lubrication (MQL), wherein the lubricant is to apply in a form of fine, uniform and highly penetrable and wettable mist droplets directly to the cutting zone. This study investigates the effect of EMQL in end milling of AISI 304 stainless steel in comparison with dry, wet and MQL machining. The results suggest that EMQL reduces tool wear and cutting force, prolongs tool life considerably and enhances surface finish compared with conventional wet and MQL machining. scanning electron microscopy and Energy-dispersive X-ray spectroscopy analyses show that EMQL considerably reduces adhesive and abrasive wear on the flank face because of the lower friction and heat generation resulting from more efficient entry of the lubricant into the cutting interfaces.     

The effect of extremely low lubricant volumes in machining

Cost, the effect on the environment, and health issues are all relevant when considering the choice of a lubricant and application system in a modern metal cutting process. The need to use less, limit the disposal and operator contact are all now very important. This paper shows the results of preliminary tests using very low quantities (200–300 ml h⁻¹) of lubricant when machining steel. The low quantities were applied in a fast flowing air stream. The results are compared to traditional flood cooling as a benchmark with 5.2I min⁻¹. The results show that surface finish, chip thickness and force variation are all affected beneficially with the low coolant volume compared to flood cooling.     

OPTIMAL MQL AND CUTTING CONDITIONS DETERMINATION FOR DESIRED SURFACE ROUGHNESS IN TURNING OF BRASS USING GENETIC ALGORITHMS

The evolving concept of minimum quantity of lubrication (MQL) in machining is considered as one of the solutions to reduce the amount of lubricant to address the environmental, economical and ecological issues. This paper investigates the influence of cutting speed, feed rate and different amount of MQL on machining performance during turning of brass using K10 cemented carbide tool. The experiments have been planned as per Taguchi's orthogonal array and the second order surface roughness model in terms of machining parameters was developed using response surface methodology (RSM). The parametric analysis has been carried out to analyze the interaction effects of process parameters on surface roughness. The optimization is then carried out with genetic algorithms (GA) using surface roughness model for the selection of optimal MQL and cutting conditions. The GA program gives the minimum values of surface roughness and the corresponding optimal machining parameters.     

Minimised gear lubrication by a minimum oil/air flow rate

The objectives of the research project were to investigate the limits concerning possible reduction of lubricant quantity in gears without detrimental influence on the load carrying capacity.The investigations covered the influence of the oil level in dip-lubricated systems as well as the oil flow rate in spray-lubricated systems namely oil/air supply systems on power loss, heat generation and load carrying capacity. The load carrying capacity in terms of characteristic gear failure modes was determined and was compared to the results using conventional and reduced lubricant volumes with dip lubrication.Therefore in back-to-back gear tests the parameters speed, load and oil quantity were varied for examination of the four main gear flank damages: scuffing, wear, pitting and micro-pitting. The investigations showed the application potential of oil/air lubrication also for heavy duty transmissions nevertheless there exists a natural limitation for lowering the oil quantity in transmissions without detrimental influence on the load carrying capacity.     

固体润滑剂在切削加工润滑中的应用

在分析固体润滑机理的基础上 ,对国内外固体润滑剂在切削润滑中的应用进行了综合评述 ,指出了固体润滑剂在各种切削润滑方式中的作用和特点 ,指出了固体润滑剂在切削润滑中的值得重视的发展方向     

Smart lubrication via pump response interval (PRI) variation in the machining process

The development of new lubrication methods in CNC machine carriages is a current requirement in the machining industry. Previously, lubrication systems of CNC machines were only improved via injection automation approaches. This paper focuses on the lubrication mode on the linear guideways of CNC machines. Additionally, the research investigates the effects of oil injection time and the amount of the required lubricant for accurate and precise machining. This study was also concerned with variations in environmental temperature and carriage movement conditions. Oil injection amount was determined by pump response interval (PRI), which was varied for optimization. Smart optimum quantity lubrication (SOQL) was applied to overcome unexpected changes in practical parameters during machining. The optimum oil consumption of SOQL was achieved when PRI was 15 s, resulting in a reduction of oil consumption of up to 25 %. The SOQL technique is an emerging method in lubrication technology and plays an important role in alleviating the current issues that CNC lubrication systems are faced with.