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本文在–60℃和300℃两种极端环境下对经过二次时效处理的7055铝合金进行高速切削试验,采用超景深三维显微系统对刀具磨损形貌进行分析,用探针式三维表面形貌仪对切削加工表面形貌进行分析,并对切削前后的7055铝合金进行TEM微观组织分析,研究了7055铝合金在两种极端环境下的刀具摩擦磨损及表面质量.研究结果表明:在–60℃时,刀具磨损的主要形式为磨粒磨损,并出现崩刃,在300℃时,刀具磨损主要形式为氧化磨损和黏着磨损;在–60℃时,材料经过了深冷处理,硬度、脆性增强,切削加工表面质量较差;在300℃时,材料经过了回归热处理,脆硬性降低,韧性增强,切削过程中不断生成氧化膜,极大程度上提高了表面质量,延长了刀具寿命;–60℃时,TEM微观组织显示,材料弥散相变细小,在300℃时,TEM微观组织显示,材料弥散相出现大量消失,即发生回归现象.
In this paper, after 7060 aluminum alloy secondary aging treatment at -60 ℃ and 300 ℃ under high-speed cutting test, the use of ultra-deep-three-dimensional microscopy system to analyze the wear of the tool, with the probe three-dimensional surface shape The appearance of the machined surface of the 7055 aluminum alloy was analyzed by means of a profile instrument and the microstructure of the 7055 aluminum alloy was analyzed before and after cutting to study the friction and wear of the tool and the surface quality of the 7055 aluminum alloy in two extreme environments.The results show that in the - At 60 ℃, the main form of tool wear is abrasive wear, and chipping occurs. At 300 ℃, the main forms of tool wear are oxidation wear and adhesive wear. At -60 ℃, the material is cryogenic treatment, hardness and brittleness Enhanced, cutting surface quality is poor; at 300 ℃, the material after the regression heat treatment, reducing brittleness, toughness increased, the cutting process continue to generate oxide film, greatly improving the surface quality and extending tool life; At 60 ℃, the microstructure of TEM shows that the dispersion phase of the material is small. At 300 ℃, the microstructure of TEM shows that the dispersed phase of the material disappears a lot, that is, the regression phenomenon occurs.