【作者】 沈中；

【导师】 陈明； 许辉；

【作者基本信息】 上海交通大学 ， 航空宇航制造工程， 2007， 硕士

【摘要】 随着切削技术向着高速、高效、干式的方向发展,刀具涂层技术成为了左右切削技术发展的主要因素,据统计在先进制造业中80%以上都采用了涂层刀具。因此,研究刀具涂层及其性能,开发满足不同加工条件的高性能刀具涂层,对促进制造业发展具有重要意义。本文分别分析了钻削、铣削、攻丝、车削四种不同加工方式的加工特点,并给出了相应刀具涂层应该侧重考虑的因素。钻削加工主要关心涂层的高温抗氧化性、高温强度、摩擦系数;铣削加工重点考虑涂层的抗冲击韧性及高温强度;攻丝加工侧重涂层的致密性、韧性、表面润滑性;车削加工则关心涂层的高温强度等。针对钻削中碳合金结构钢40Cr、铣削淬硬模具钢SKD11、攻丝球墨铸铁QT500及车削低碳硫系易切削钢,在PLATIT PL 1000纳米真空涂层系统中开发了一系列涂层。通过系统的实验理论研究,着重分析了涂层的磨损机理、切削力、切削温度等,证明了含铝55%的AlTiN涂层、纳米复合相结构AlTiN/Si3N4涂层、多层TiCN涂层及TiN + Al2O3 + TiCN复合涂层,分别在钻削、铣削、攻丝、车削中优异的切削加工性能。为进一步理论研究刀具涂层如何改善切削性能,对涂层刀具的切削加工过程进行了有限元的建模与仿真。完成了TiN + Al2O3 + TiCN复合涂层刀具的正交切削过程的仿真,并对切削力、切削温度及刀具应力的模拟结果进行分析。切削力方面:涂层刀具的主切削力与切深抗力较无涂层刀具都要小,并且仿真结果与实验结果相一致。切削温度方面:切削温度最高发生在刀-屑接触区接近主切削刃的部位,达到450℃左右,而刀具基体的温度低于100℃,但刀具涂层产生了较大的温度梯度。刀具应力方面:最大刀具等效应力出现在刀具前刀面上靠近主切削刃的区域,同时在后刀面上也出现了比较大的应力分布。通过涂层刀具切削过程的仿真研究可知,一方面,尽可能提高涂层的高温性能,同时注意确保涂层的隔热性能避免涂层塌陷;另一方面,需要避免涂层之间、涂层与基体之间过大的温度梯度。更多还原

【Abstract】 Cutting tool coating technology has been widely applied and will play a vital role in advanced cutting technology, which will boost the cutting technology to a new trend of development– high speed, high efficiency and dry cutting. In addition, it is reported that more than 80% of cutting tools are coated in the area of advanced manufacturing. Therefore, studying of the cutting tool coating and its performance, developing high quality coating for various cutting condition, will contribute to the development of manufacturing.In this work, the specific properties of drilling, milling, tapping and turning were rounded studied for the sake of providing the preferred factors for which coating should consider. The oxidation resistance and friction coefficient, the resistance of impact toughness, the compactness and surface quality, and the intensity under high temperature were the priority factors for drilling, milling, tapping and turning processes respectively. According to these preferred factors, a series of coating were developed in the PLATIT PL1000 Nano-scale Vacuum Ion Coating system for different cutting applications which were listed as follows, AlTiN coating with 55% Al content for drilling of mid-carbon structural steel 40Cr, AlTiN / Si3N4 coating for milling of SKD11, multilayer of TiCN coating for tapping of QT500 and composite coating of TiN + Al2O3 + TiCN for turning of low carbon sulphur free cutting steel. Their high performances were revealed by systemic experimental study, particularly in analyzing the coating wear mechanism, cutting force, cutting temperature etc. In order to further study the cutting process considering the coating effects, a Finite Element model was developed for simulating the cutting process with coated tool. The composite coating of TiN + Al2O3 + TiCN was built for simulating the orthogonal cutting and several properties such cutting force, cutting temperature and effective stress on the cutting tool were studied. This part of study indicated that the cutting forces using coated tool were smaller than that of uncoated tool, and the simulated result of cutting force were consistent with the experimental result which showed the simulation was creditable. The highest cutting temperature was occured on the tool-chip interface near the cutting edge, which can arrive at about 450℃, but the temperature on the substrate was less than 100℃. Furthermore the relatively high temperature gradient was found in the coating. The highest effective stress was also appeared on the tool-chip interface near the cutting edge, and some high stress was discovered on the flank face. Though the simulation of cutting process, some tips in design coating are approached. On the one hand, the resistance of high temperature should be developed as possible, and the thermo insulating property should also be enhanced in order to avoid subside. On the other hand, the temperature gradient should be avoided which will raise inner stress between coatings.更多还原