冷风切削对高速切削难加工材料刀具磨损的影响

Effect of Refrigerated Air Cutting on Tool wear in High-speed Cutting of Difficult-to-cut Materials

基于复合制冷技术研制1种低温冷风/低温最小量润滑供给装置,使用TiAlN涂层硬质合金刀具进行干切削、最小量润滑(MQL)、低温冷风及低温最小量润滑(低温MQL)条件下镍基高温合金Inconel 718的高速车削试验和淬硬钢AISI D2的高速铣削试验,通过扫描电镜(SEM)和能谱分析(EDS)观察分析硬质合金刀具的磨损形态、磨损机理,研究低温冷风和低温MQL对高速切削难加工材料刀具磨损的影响.结果表明:高速切削Inconel 718和AISI D2时,刀具磨损机理主要为磨料磨损、黏结磨损和扩散磨损;低温冷风和低温MQL可有效降低高速切削时的切削温度,进而防止刀具软化,减小磨料磨损和与温度相关的黏结磨损、扩散磨损,因而可大幅度地提高刀具的使用寿命.

A refrigerated air/cryogenic minimum quantity lubrication generator was developed based on a composite refrigeration method. TiMN coated carbide tool was used in high - speed turning of Inconel 718 nickel - base superalloy and high - speed milling of AISI D2 hardened steel. Experiments were conducted under different cooling/lubrication conditions, i.e. dry cutting, minimum quantity lubrication （MQL）, refrigerated air, and cryogenic minimum quantity lubrication （ cryogenic MQL）. SEM and EDS were used to analyze wear morphologies and mechanism of cemented carbide tools. Thus effect of refrigerated air and cryogenic MQL on tool wear was investigated in high - speed cutting of difficult - to - cut materials. The results showed that the main tool wear mechanism was abrasive wear, adhesive wear and diffusion wear in high - speed cutting of difficult - to - cut materials. Application of refrigerated air and cryogenic MQL in the high - speed cutting of difficult - to - cut materials reduced the cutting temperature effectively, which avoided the intenerate of cutting tools, and reduced abrasive wear and thermally related wear such as adhesive wear and diffusion wear. Therefore, refrigerated air and cryogenic MQL enhanced tool life remarkably.