Research On Basic Issue Of Microscale Milling Process

As higher and higher degree of product miniaturization and precision, the processing difficulties and the machining precision requirements are also more and more high, micro-dimensional milling is one of the important methods of micro-precise machining. Micro-dimensional milling has unique advantages to satisfy diversities of processing materials and realize the three-dimensional curved surfaces’ machining, so it has been widely used in microelectronics, aerospace, biomedical engineering, precision equipment manufacturing and other fields. The machining of miniature and complicated, high strength and precision, multi-scale structure constituents puts forward higher requests for micro-dimensional milling technology. These things urgently need us to carry on in-depth researches of basic theory knowledge about micro-dimensional milling, and summarize and explore process methods of it. Some developed countries in overseas, attach great importance to developing micro-dimensional machining technology, invest a lot of manpower and financial resources and set up specialized research institutions, to promote rapid development of micro-dimensional processing technology, and have initially formed distinctive micro-dimensional machining technology and micro products manufacturing. Our country started later, is currently in the stage of exploration research.The phenomenon such as size effect, minimum cutting thickness and tool wear are important aspects for mechanism researches of micro-dimensional milling. In addition to, focusing on research about cutting temperature, micro milling force, micro burrs, processing quality and vibration in micro milling process is also a key point in research on micro-dimensional milling machining. This article conducts research by combining experiments and simulation, the main content includes the following aspects:Firstly, through using finite element analysis software ABAQUS, respectively establishing two-dimensional orthogonal, vertical angle cutting model and a simplified two-dimensional milling model to carry on the simulation research and analysis on micro-dimensional milling machining. By two-dimensional orthogonal, vertical angle cutting model, exploring the influences of cutting depth and feed speed on temperature field of work-piece and tool and cutting force; through a simplified two-dimensional milling model, analyzing the influences of spindle speed on temperature field of work-piece and tool.Secondly, related laboratory equipments and testing instruments are introduced in detail. Carrying on milling experiment of TC4titanium alloy by using different diameters and different blade numbers of micro milling cutter with different milling parameters in micro machine tools, to study influences of axial cutting depth, feed speed, spindle speed and linear velocity, feed engagement on milling force, milling surface roughness and surface topography. On the basis of analyzing the formation mechanism of micro milling burrs, further studying and analyzing the affects of axial cutting depth, feed speed and tool wear on burrs by designing experiments. Researching the wear mechanism of micro milling cutter, and qualitatively, comparatively analyzing the wear conditions and characteristics of micro milling cutter under different blade diameters and different numbers of cutting edge, to providing the certain basis for the micro milling machining, and further exploring the influences of micro milling cutter wear on milling surface, meanwhile, processing surface quality can reflect tool wear.Due to indispensable influence of vibration for micro milling machining, by using three-dimensional piezoelectric acceleration sensor in experiments, measuring the vibration of work-piece and machine tool spindle and exploring different states and period of vibration in micro-dimensional milling machining, studying the influences of the spindle speed on machine tool spindle vibration, comparatively analyzing the milling machine tool vibration unprocessed and in the process of milling machining, exploring the effects of milling parameters on milling vibration.