碳化硅反射镜安装面电火花平动加工工艺及试验研究

【作者】 王昆；

【导师】 汪炜；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2016， 硕士

【摘要】 碳化硅(SiC)材料由于具有低热膨胀系数、高强度等显著特点,受到了越来越多的重视。但由于其高硬脆性,传统机械方法周期长、成本高,本文提出了一种加工碳化硅反射镜安装面的电火花平动加工方法,研究了材料去除机理,通过工艺即试验研究,验证了该方法的可行性。本文的主要内容如下:1.利用有限元仿真软件ANSYS对电火花平动加工的温度场和流场进行了仿真,探究脉冲宽度、峰值电流以及不同冲液方式对电火花加工温度场和流场的影响规律。仿真结果表明,随着脉冲宽度和峰值电流的增大时,蚀除效率相应提高,表面粗糙度也随之增大;此外,内部冲液的加工稳定性要优于侧面冲液。2.设计了电火花平动加工石墨电极,采用内部冲液和微动进给方式,搭建了电火花平动加工试验系统。3.设计了单因素试验和正交试验,研究了各工艺参数对电火花平动加工材料去除率和表面粗糙度的影响规律,并在大口径(安装面直径1.23米)碳化硅反射镜安装面上进行试验,证明了碳化硅材料大平面的电火花平动加工可行性。更多还原

【Abstract】 Silicon carbide(SiC) material has low thermal expansion and high strength, so it attracts more and more attention. But due to its high hardness, if it is machined by the traditional mechanical method, the cycle will be long and the cost will be high. This paper proposes a new method for the fabrication of the SiC mirror installation plane, the EDM planetary maching. The paper studies its processing mechanism and proves the feasibility of this method by technology and experiments. The main contents are as follows:1.Using the software ANSYS, which is used for finite element simulation, to analysis the influence rules of pulse width,the peak current and different liquid ways on temperature field and flow field. The simulation results show that when increasing the pulse width and the peak current, the removal efficiency will improve and the roughness will increase. In addition, internal flushing liquid way is much better than side flushing way.2.Design EDM planetary machining graphite electrode, use internal flushing method and micro feed way, build the EDM planetary machining experiment system.3. Design the single factor experiments and orthogonal tests, study the influence rules of every technology parameters on EDM planetary machining Material removal rate and surface roughness. And test on large diameter SiC mirror installation plane, grind its surface, which proves that EDM planetary maching method is feasible.更多还原