应用MarkingMate与MasterCAM进行个人印章的加工

主要介绍了使用FANUC-Oi数控铣床完成个人印章示范加工过程.具体阐述了如何利用MarkingMate软件创建个人印章,以及如何实现MarkingMate与MasterCAM文件格式的转换.详细说明了在MasterCAM中的程序编制过程,包话采用的毛坯、刀具、选取工艺参数,后处理设置等.最后借助PCIN软件完成程序的传输,实现从设计到加工一体化过程.该项目的示范教学,激发了学生后续学习数控课程的兴趣,对学生自主学习能力起到一定促进作用.     

车床轴向长度可调式定位装置的研究

轴类零件在加工时,先平端面、定长度,再将毛坯其他部位余料去除,使其尺寸符合图纸要求。在此工序中,需要多次重复完成装夹、切削加工、检测等工作,才能得到合格的零件,工作重复、繁琐、容易出错,甚至还会造成加工零件的报废。为了减轻劳动强度,节约零件加工时间和成本,简化操作过程,改进制作了一个使用方便、装夹快速的工装来完成轴端面的加工。     

细长梁类零件的加工技术探究

细长梁类零件是飞机上一种重要的结构件,因其结构特殊,使得加工难度大。着重对细长梁类零件的加工方法进行分析探究,并对工艺方案进行了论证。工艺方案已通过加工验证,对细长梁类零件的加工具有非常重要的指导性意义。     

铝合金半连续铸造机冷却水量探讨

本文针对铝合金半连续铸造机冷却水量,从铸造机结晶器冷却供水的工作原理、理论计算、实例分析人手,探讨如何做到冷却水量既合理又节约。     

基于SOV的机械产品装配过程质量因素耦合模型

为提高机械产品的装配精度,从而最终提高装配质量稳定性,提出了一种基于SOV理论的机械装配过程质量因素耦合模型.利用灰色关联分析法,识别机械装配过程中影响产品质量的因素,在此基础上,利用状态空间方程构建机械装配系统的误差传递模型,以实现质量影响因素耦合关系的定量分析,提高机械装配过程质量控制与优化策略的时效性.最后以HFUTIE-MES为应用实例,验证了上述方法的可行性和实用性.     

The Causes and Prevention of Smut on Etched AISI 300 Stainless Steels

During the fabrication of stainless steel parts by photochemical machining (PCM), a seemingly random occurrence of a partially-adherent, brown/black deposit, known as smut, can occur. This quality problem has plagued the PCM industry for over 30 years. In the past, the problem has been attributed to “poor etch-quality” stainless steel. However, an extensive investigation by the authors, comprising some 7 person-years of effort, has established that while the metallurgy of the stainless steel has some influence on the formation of smut, by far the most important factor is the condition of the ferric chloride etchant used for etching the parts. The influences of etchant concentration, free hydrochloric acid content, temperature, atmosphere and hydrodynamic flow have now been assessed quantitatively for the first time. The investigation has led to the development of a theory outlining the causes of smut formation, thus providing solutions for its prevention.     

Surface treatment of cutting tool substrates

Today's research activities are concentrated on improving the properties of cutting tools by optimizing manufacturing technologies, by alloying of special cutting materials and by coating of tools. As a result of the poor machinability of new cutting materials, grinding processes get more difficult. Especially in grinding of new WC-carbide and cermet compositions, high mechanical and thermal loads influence the surface topography and surface integrity of the tool. In particular, the coating adhesion depends on the surface structure of the substrate. Variations of subsurface properties cause distinct differences to interface strength and tool life.Influences of surface properties on film adhesion of PVD-coated carbides were investigated. Considered topics are the influence of grinding, micro blasting and water peening of carbides on surface topography and surface integrity as well as effects on film adhesion of (Ti,AI)N-coatings. Residual stress measurements and SEM-pictures were used for characterization of surface properties. Film adhesion was analysed by scratch and indentation tests. Due to increasing interface strength of micro blasted tools a superior wear behaviour in dry machining was observed.     

Micro-mechanical and fracture characteristics of Cu6Sn5 and Cu3Sn intermetallic compounds under micro-cantilever bending

This study focuses on the fracture characteristics of Cu₆Sn₅ and Cu₃Sn micro beams under micro-cantilever bending tests. These micro beams were fabricated by focused ion beam (FIB) from the Sn-rich solder joints aged at 175 °C for 1132.5 h, and then tested using a nanoindenter with a flat tip. Experimental results show that both Cu₆Sn₅ and Cu₃Sn micro beams underwent elastic deformation before their failure. From fractographic analysis, both cleavage fracture and intergranular fracture can be identified from the tested Cu₆Sn₅ micro beams, while only intergranular fracture was found in Cu₃Sn micro beams. Furthermore, based on the experimental results, finite element analysis was carried out to evaluate the tensile fracture strength and strain of Cu₆Sn₅ and Cu₃Sn micro beams. For Cu₆Sn, the tensile fracture strength was estimated to be 1.13 ± 0.04 Pa and the average tensile strain was 0.01. The tensile fracture strength and strain of Cu₃Sn were evaluated to be 2.15 ± 0.19 GPa and 0.016, respectively.     

Wire electrical discharge machinable SiC with GNPs and GO as the electrically conducting filler

SiC based composites filled with graphene nano-platelets (GNPs) or graphene oxide (GO) prepared by rapid hot-pressing exhibit sufficient electrical conductivity for their machinability by wire electro-discharge machining (WEDM). Composites microstructure anisotropy caused by graphene alignment as a consequence of rapid hot pressing was confirmed by measuring of electrical conductivity and thermal diffusivity. Electrical conductivity increased significantly with increased weight fraction of graphene in both measured directions. Highest value of 2031 S/m was obtained for composites with 15 wt. % of GNPs in parallel direction and only 1246 S/m in perpendicular direction to aligned GNPs. Thermal diffusivity is 63.3 mm²/s in parallel and only 23.3 mm²/s in perpendicular direction. The increase of the electrical conductivity has resulted in successful WEDM. The MRR was almost doubled when the filler concentration increased from 5 wt. % GNPs/GO to 15 wt. % GNPs. At the same time, the surface roughness decreased.     

Laser induced oxidation of cemented carbide during micro milling

Cemented carbide is widely used as precision mold material due to its superior properties. The excessive tool wear and short tool life are the main problems during micro cutting of cemented carbide. Firstly, the high temperature oxidation behavior of cemented carbide under laser irradiation was studied in this paper. Cemented carbide surface can be induced to fully oxidize and generate highly porous oxide layer which is much easier to remove with micro milling tool. Then, the micro milling hybrid process assisted with laser induced oxidation of cemented carbide was proposed. Micro milling experiments assisted with and without laser oxidation were performed on WC-15Co cemented carbide. It is found that the hybrid machining process can greatly reduce the tool wear and cutting force, and also achieve fine surface finish.