机械制造技术英文PPT (18).ppt

Mechanical Manufacturing TechnologyHigh Speed Cutting And GrindinguOverview The famous Salomon curve given by the German physicist C.J.Salomom in his article on the principle of high-speed cutting in 1931there is a critical cutting speed corresponding to a certain workpiece material,the cutting temperature gets higher with the cutting speed below the critical value.However,the cutting speed increases and the cutting temperature decreases above this critical value.Salomoms theoretical and experimental results generated a great deal of interest and led to the concept of High Speed Cutting(HSC).3.8.1 Overview of high-speed processingu High-speed processing definition There is no unified definition,but it is generally considered that high-speed machining refers to modern machining technology that uses super-hard material tools to improve material removal rate,machining accuracy and surface quality by greatly increasing cutting speed and feed rate.Defined by cutting speed and feed rate:The cutting speed and feed rate of high-speed machining is 5 to 10 times that of ordinary cutting.Defined by spindle speed:spindle speed 10000 r/min for high-speed machining.figure 3-31 Salomon Cutting temperature and cutting speed curvecutting adaptation zonesoft aluminumcutting speed v/(m/min)cutting maladjustment zone0 600 1200 1800 2400 3000bronzecast ironsteeltungsten carbide980high speed steel650Carbon tool steel450Stelite alloy 8501600 1200800400切cutting temperature/cutting adaptation zonenon-ferrous metal3.8.1 Overview of high-speed processingfigure 3-32 High and ultra-high cutting speed range 10 100 1000 10000 cutting speed V（m/min）plasticaluminum alloycoppercast ironsteeltitanium alloynickel alloyu Range of cutting speeds for high-speed machining The The range range of of cutting cutting speeds speeds for for high-speed high-speed machining machining varies varies depending on the workpiece material,see figuredepending on the workpiece material,see figure3-323-32turning：700-7000 m/minmilling：300-6000 m/mindrill：200-1100 m/mingrind：50-300 m/s The range of cutting speeds for high-speed machining varies depending The range of cutting speeds for high-speed machining varies depending on the machining methodon the machining method3.8.1 Overview of high-speed processingHigh processing efficiency：Feed rate is 5-10 times higher than conventional cutting and material removal rate is 3-6 times higher.Low cutting force：The radial force is reduced by at least 30%compared to conventional cutting,and the reduction is more pronounced.It helps to reduce the deformation of the workpiece and is suitable for thin-walled and long-walled parts.Low cutting heat：Rapid processing,more than 95%of the cutting heat is carried away by the chips,the workpiece accumulates very little heat,low temperature rise,suitable for processing low melting point,easy oxidation and easy to produce thermal deformation of the parts.u Features of high-speed processing3.8.1 Overview of high-speed processingHigh processing accuracy：The tool excitation frequency is far from the inherent frequency of the process system and is less prone to vibration.It has small cutting force,small thermal deformation,small residual stress,easy to ensure machining accuracy and surface quality.process intensification：High machining accuracy and low surface roughness can be achieved,and hard surfaces can be machined under certain conditions,allowing for process intensification.This is of particular significance for mold processing.u Features of high-speed processing3.8.1 Overview of high-speed processingaerospace：Machining Machining of of large large light light alloy alloy monolithic monolithic components components with with a a large large number number of of thin thin walls walls and and thin thin bars bars with with a a material material removal removal rate rate of of 100-100-180180cmcm3 3/min/min.Nickel and titanium alloys with cutting speeds up to 200-1000 m/min.Nickel and titanium alloys with cutting speeds up to 200-1000 m/min.automotive industry：u Applications for high-speed processing High-speed High-speed CNC CNC machine machine and and high-speed high-speed machining machining center center are are used used to to form form a a high-speed high-speed flexible flexible production production line line to to achieve achieve efficient efficient production production of multiple varieties and small and medium batches.of multiple varieties and small and medium batches.（figure figure 3-333-33）mould making：High-speed milling replaces traditional EDM forming with 3-5 times higher High-speed milling replaces traditional EDM forming with 3-5 times higher efficiency.efficiency.（figure figure 3-343-34，figure figure 3-35 3-35）.3.8.1 Overview of high-speed processingu Applications for high-speed processinginstrumentation：Precision optical parts machining Precision optical parts machining.3.8.1 Overview of high-speed processinguu Although Although high-speed high-speed processing processing h。