电火花内圆磨削伺服阀阀套及表面质量分析

主要论述电火花内圆磨削加工的机理、加工特点,并通过实验和使用所取得的数据,较全面地分析了电火花内圆磨削加工阀套内孔、内环槽的电参数对表面质量的影响。     

我国超精密加工设备的产业化进程

我国机床制造业在世界上已经占有一席之地,但生产的绝大多数依然是普通级精密机床,而超精密加工设备尚未达到工业化生产水平,一些关键元部件还依赖进口,自主研制价格高、周期长,缺乏精度稳定性和设备运行的长期稳定性.应在重视超精密基础元部件研发的基础上,联合国内优势单位组建超精密加工设备产业化研发和生产基地,加强超精密加工设备产业化开发,满足国家重大型号任务的需求.     

麻花钻双曲面刃磨的数学模型及参数计算方法

介绍了以回转双曲面作为麻花钻后刀面的数学模型 ,设计参数与刃磨参数的关系。针对该钻型的特点 ,提出用钻尖主刃的外缘和横刃转点处的锋角作为其设计参数值。并以尾隙角为补充参数 ,惟一地确定钻尖的刃磨参数。给出了该钻型设计参数与刃磨参数之间的函数关系式 ,为双曲面麻花钻型的设计和刃磨提供了一定的理论基础。     

K417航空叶片材料缓进深磨烧伤特征及烧伤程度判别

 利用扫描电镜、电子探针、x射线光电子谱仪等测试分析手段,按照传统的烧伤分档标准对K417铸造镍基高温合金缓进磨削时烧伤表面的形成机理及烧伤表面层物理性态所发生的种种变化进行了系统的研究。文中针对高温合金本身的特点,结合性态测试与疲劳试验结果指出:仅有紫色档才可能对零件的使用寿命构成实质性损伤。     

精密石墨零件的研磨

介绍了以石墨Ｍ１０６Ｈ为材料的密封环的研磨加工,重点介绍了研具,研磨剂及工艺步骤。     

Thermomechanical coupling effect on characteristics of oxide film during ultrasonic vibration-assisted ELID grinding ZTA ceramics

Ultrasonic vibration-assisted ELID (UVA-ELID) grinding is utilized as a novel and highly efficient processing method for hard and brittle materials such as ceramics. In this study, the UVA-ELID grinding ZTA ceramics is employed to investigate the influence of thermomechanical loading on the characteristics of oxide film. Based on the fracture mechanics of material, the model of internal stress for oxide film damage is proposed. The thermomechanical loading is composed of mechanical force and the thermal stress generating from grinding temperature. The theoretical model is established for the mechanical force, thermal stress and internal stress respectively. Then the finite element analysis method is used to simulate the theoretical model. The mechanical force and grinding temperature is measured during the actual grinding test. During the grinding process, the effect of grinding wheel speed and grinding depth on the thermomechanical force and the characteristics of oxide film is analyzed. Compared with the conventional ELID (C-ELID) grinding, the mechanical force decreased by 25.6% and 22.4% with the increase of grinding wheel speed and grinding depth respectively, and the grinding temperature declined by 10.7% and 12.8% during the UVA-ELID grinding. The thermal stress in the latter decreased by 16.3% and 20.8% respectively, and internal stress reduced by 12.3% and 15.6%. It was experimentally found that the topographies of oxide layer on the surface of the wheel and the machined surface in the latter was better than that in the former. The results indicate that the action of ultrasonic vibration establish a significant effect on the processing. Subsequently, it should be well considered for future reference when processing the ZTA ceramics.     

定向凝固镍基高温合金叶片榫齿高效深切成型磨削

针对定向凝固镍基高温合金DZ125叶片榫齿,采用电镀成型CBN砂轮对其进行了高效深切磨削(High efficiency deep grinding,HEDG)试验,对磨削比能及工件表面完整性进行了分析。结果显示,在保持速比(vs/vw)不变时,提高磨削速度vs可有效降低磨削比能,提高平均材料去除率。磨削比能表现出"尺寸效应",其值最终稳定在40~60J/mm3之间;在相同的平均材料去除率下,磨削比能随着磨削深度的增大而上升;在相同的单颗磨粒切厚下,磨削深度的差异对磨削比能的影响较小。对试验中最大平均材料去除率下获得的工件表面质量进行分析发现,已加工工件表面不同区域磨削纹理均很清晰,无皱叠及犁沟两侧翻起等现象;表层金相显微组织基本无变化,未发现相变、撕裂及晶粒扭曲现象;工件表层加工硬化程度为7.7%~19%,深度为40μm。结果显示了HEDG在高效磨削DZ125叶片榫齿中推广应用的潜力,并为其实际生产中磨削参数的选择提供了参考。     

熔融石英高效精密磨削技术的研究

介绍了运用电镀金刚石磨轮干磨削技术,实现对熔融石英高效精密加工的磨削工艺.     

平面磨削形状误差的分析

提出了平面磨削形状误差的产生模型,并通过实验验证了其模型的合理性,同时揭示了各种要素对形状误差的影响规律,选定了能使形状误差最小的磨削加工条件。     

球头模具铣刀刀刃和前刀面成形的研究

提出了一种使球头模具铣刀具有良好切削性能,可以大大改善球顶点及其附近处切削条件的刀刃构造形式和前刀面形状;根据包络原理详细分析和研究了成形这种球头铣刀刀刃及前刀面的磨削（或铣削）系统的合理运动方式,并导出了各运动间的函数关系;给出了一计算实例。