基于三种不同材料的超光滑表面性能测量结果的对比研究

为了研究目前主流微加工表面检测方式,本文选择三种基本材料：K9玻璃、金属、陶瓷三种不同材料在同等条件下采用不同工艺进行加工,并使用目前主流超光滑表面测试仪器对其进行检测。通过对照结果,分析各仪器测量原理、分辨力决定因素,区分造成测量误差的原因及它们各自对粗糙度参数的影响。     

封面广告简介

国家科委成果办推荐使用——RM-20表面粗糙度仪 工件表面粗糙度对工件加工的经济性、使用功能及寿命都有着重要的影响,传统的粗糙度测量仪器体积大,造价高,不适于现场作业,采用比较样块又使测量精度降低。针对上述缺点,北京市时代机电新技术公司开发研制出 TIME RM——20表面粗糙度仪,已通过中国计量院的定型鉴定,该仪器属国家科委火炬计划项目,采用微处理机及高度集约化的电路设计,可一次完成粗糙度参数(Ra、Rz)的采集与显示工作。 RM—20采用压电式触针测量方式,可在0℃～40℃常温下直接测量被加工工件的平面、外圆、锥面,以及大于 8…     

玻璃光滑度测量仪

据俄罗斯最新一期《科学信息》杂志报道,俄专家开发出一种利用白光测量磨光玻璃表面光滑度的仪器,可以准确快速地辨别玻璃表面的突起或凹陷。新测量仪器的开发借助了普通白光的干涉原理。工作时,该仪器将一束白光平分成完全相同的两束白光,并分别照射表面光滑的标准玻璃和需要检测表面磨光程度的玻璃,然后将两片玻璃的反射光线“合成”一条光线。通过电脑分析,可以得知两条反射光线所走过的路程长短。科学家介绍说,如待检玻璃表面有突起,则反射光线走过的路程会比标准玻璃的反射光线走过的路程短;而如待检测量玻璃表面有凹陷,效果则相反。通…     

覆层测厚仪在测量时的基体选择

针对覆层测厚仪在实际应用中常常出现测量不准、误差较大的问题,探讨基于磁感应测量原理、电涡流测量原理的覆层测厚仪的特殊性,分析了影响测量结果的诸多因素.分别对两种覆层测厚仪用不同材料的基体及不同表面粗糙度的基体校准、测量,得到对比实验的几组数据,说明测量误差产生的原因,强调在测量时基体的选择和仪器的校准方法,以及减小测量...     

国产2201型电动轮廓仪的改造

国产2201型(哈量)电动轮廓仪是根据测量Ra或Rz而设计的表面轮廊特征参数测量仪器。如何对该仪器进行技术改造,使之满足表面粗糙度国家标准GB1031—83中规定的六项基本参数的测量,我们进行了微机化的研究。     

非球面玻璃镜片四轴磨削加工误差分析及其补加工

非球面玻璃镜片四轴磨削加工的加工硬件和加工工艺都具有很强的专业性,因而产品的加工精度控制问题显得十分突出。以玻璃镜片精加工后表面粗糙度和面型精度为加工精度指标,对加工过程进行了详细分析,总结出误差产生的原因以及各种误差对加工结果的影响。结合对误差数据的分析,给出了相应的补加工解决方案,生成补加工轨迹。     

超光滑表面纳米压痕硬度测试研究

介绍纳米压痕法常用的Oliver-Pharr方法的计算原理,对硬度的概念做了进一步讨论。通过对三种不同材料的超光滑表面进行硬度测试,得出它们各自的硬度值和弹性模量,分析了结果差异的原因,探讨了在采用Oliver-Pharr方法进行硬度各参数测量时应注意的问题,分析结果对超光滑表面加工也有一定的指导意义。     

光纤式表面粗糙度测量仪的研制

本文论述了光纤表面粗糙度测量仪研制过程中关键问题的解决方法，对非线性特性的参数计算，零点漂移，信号噪声，不同加工表面特性差异的处理都给出了完美的解决方法。该仪器以光散射理论为测量原理，用光纤为传输媒介，并用单片机８０９８进行计算，数据处理和测量智能控制。     

单晶金刚石机械研磨与化学机械抛光工艺

单晶金刚石在工业、国防等领域的应用日益广泛,对其加工表面质量的要求不断提高,使用常温低压的化学机械抛光可实现金刚石的超光滑低损伤表面加工.通过理论分析及实验研究得出,使用硅酸盐玻璃材质研磨盘进行研磨加工,可以将金刚石表面粗糙度Ra降至15~25 nm,且无明显机械划痕;在2 MPa压力及室温环境下进行单晶金刚石化学机械抛光实验,优选出Fenton试剂酸性水基抛光液,使用该抛光液抛光单晶金刚石可获得粗糙度Ra值4 nm以下的光滑表面.     

光纤式表面粗糙度测量仪的研制

本文论述了光纤式表面粗糙度测量仪研制过程中关键问题的解决方法，对非线性特性的参数计算、零点漂移、信号噪声、不同加工表面特性差异的处理都给出了完美的解决方法。该仪器以光散射理论为测量原理，用光纤为传输媒介，并用单片机８０９８进行计算、数据处理和测量智能控制。     

用立方氮化硼刀具对硬质合金材料进行延性超精密加工

对单相晶体结构和硬质合金的粘合特性的理论分析表明，对其进行延性超精密加工是可行的，并在普通加工中心上通过对切削力的监控，用立方氮化硼刀具实现了对硬质合金材料的延性超精密加工．研究结果显示，在用不同刀具进行的切削中，刀具的磨损都非常小；在对硬质合金的延性超精密加工中获得了纳米级表面粗糙度的平滑表面和层状切屑。     

纳秒脉冲激光对316L不锈钢微抛光效果的影响

激光微抛光过程中,激光的能量密度对微抛光效果的影响很大.采用纳秒紫外脉冲激光(波长为355 nm,脉冲宽度为35 ns)对316L不锈钢材料进行微抛光实验研究,分析了工件表面的形貌、扫描速度和离焦距离等因素对激光微抛光效果的影响.通过对4种不同表面形貌的抛光效果比较,发现不仅表面粗糙度会影响抛光质量,而且表面的形貌也对激光微抛光的效果有很大影响;激光微抛光时对确定的激光能量密度存在最佳微抛光效果的扫描速度和离焦距离.提出了355 nm紫外纳秒脉冲激光器对316L不锈钢微抛光效果的最佳工艺参数:激光能量密度为0.14 J/cm2,激光脉冲重复频率为20 Hz,扫描速度为18.6 mm/min,离焦距离为81.2μm.在此工艺参数下,316L不锈钢经过微抛光之后,表面粗糙度由123.23 nm降低至80.96 nm.     

基于激光二维散射原理在线测量表面粗糙度

针对现有零件表面粗糙度测量仪器操作复杂,现场测量能力差的问题,提出一种基于激光二维散射的在线测量方法,该方法不仅可以测量表面粗糙度的统计参数,而且可以反映出表面纹理的形貌特征.在测量中,用无衍射激光光束作光源,用高精度的CCD摄像机作位移传感器,利用Matlab进行表面粗糙度测量数据采集与处理,使表面粗糙度在线检测成为...     

Beeinflussbarkeit der Bauteilgestalt durch Prozessstellgrößen beim Außenlängsdrehen von AlSi9Cu3 ‐ GJS400 Parallelverbunden

Influence of the process variables on the workpiece form accuracy in the machining of parallel compounds out of AlSi9Cu3 ‐ GJS400 To guarantee excellent work piece quality for the machining of compound materials characteristic interactions between the components have to be considered in the process design. Especially by parallel compounds, where the different components are processed in an alternating manner, the machinability of the compound differs considerably from the machinability of each homogeneous component. Depending on the compound partner the surface topography of a component can vary considerably. Rotationally symmetric compound work pieces primary hold radius and transition deviations. In addition to unequal tool and workpiece deflection the radius deviations results from the different topographies in each component. The surface topography and its measurement methods as well as the process parameters and their influence on the process forces have to be considered for a proper process design.     

浅谈农机零配件表面粗糙度的测量

阐述了表面粗糙度对零件使用性能的影响及评定表面粗糙度的基本原则，叙述了零件表面粗糙度的几种测量方法，以及使用针描法测量零件表面粗糙度应注意的问题。     

大口径光学镜面超精密加工机床的研制

设计制作了最大加工直径为φ880 mm的光学镜面超精密加工机床.该机床采用大理石床身、4轴数控联动、全气浮支承和零传动结构,以实现光学球、非球及自由形面的超精密切削.介绍了机床整体结构特点和性能参数,描述了气浮电主轴、气浮直线导轨、直驱回转工作台等关键技术及部件.该机床主轴回转精度0.05μm,直线伺服轴分辨力1.25 nm,回转工作台角位移分辨力0.009.″在硬铝和无氧铜材料上分别加工出了面形精度0.5μm、表面粗糙度5 nm的φ400 mm球面和面形精度0.5μm/φ100 mm、表面粗糙度8 nm的非球形面.     

检测表面粗糙度的光纤传感器研究

论述了测量表面粗糙度的反射散射比光纤传感器的结构、工作原理。介绍了它具有的抗干扰能力强、测量精度高、重复性好、可测微小面积和孔洞底面等异型表面等特点。给出了实测结果 ,并对影响测量的各种因素进行了分析讨论     

小口径非球面的超精密车削和抛光组合加工

针对目前小口径非球面零件在超精密加工中存在的加工效率和加工精度等问题,分析了现今小口径非球面超精密加工方法及其特点,提出了一种超精密金刚石车削和斜轴磁流变抛光超精密组合加工方法．其中小口径非球面斜轴磁流变抛光方法的特点是抛光主轴采用倾斜安装,并且抛光头由外部旋转抛光体和内部励磁装置两部分构成．通过开发新型的小口径非球面超精密复合加工装备,对小口径单晶硅非球面进行了超精密组合加工实验．实验结果表明工件的表面粗糙度R。由车削后的9．1nm下降到抛光后的3．2mm,证明了该组合加工工艺是提高小口径非球面加工效率和精度的一种有效加工方法．     

Numerical analysis and experimental validation of surface roughness and morphology in honing of Inconel 718 nickel-based superalloy

Honing is an important technology for machining onboard system parts. The parts are usually made of difficult-to-machining materials, e.g., Inconel 718 superalloy. Honing can improve the finishing accuracy and surface quality. However, the selection of the honing parameters was primarily based on the results of a large number of experiments. Therefore, the establishment of a reliable model is needed to predict the honed surface roughness and morphology, and offers a theoretical direction for the choice of parameters. In the present study, a numerical simulation model was constructed for analysis of the honing process by Python. The oilstone, workpiece surface morphology and motion trajectory were discretized by Python, and the machined surface was obtained by trajectory interference. Firstly, based on the statistical analysis of the surface topography of oilstone, the shape of grains was simplified and the surface topography of oilstone was built accordingly. Then, the initial surface morphology of the workpiece was constructed and the trajectory of grains on the workpiece surface was analyzed, which showed the distribution of the removed material. Meanwhile, the plastic deformation of material was analyzed in the simulation model. The critical depth of three stages of contact between grains and workpiece was calculated by the theoretical formula: scratching, ploughing and cutting. By analyzing the distribution of bulge, the plastic deformation in ploughing and cutting stage was studied. Further, the simulated results of honed surface roughness and morphology were validated and agreed reasonably well with the honing experiment. Finally, the effects of honing process parameters, including grain size, tangential speed, axial speed, radial speed and abrasive volume percentage, on the surface roughness of the workpiece were analyzed by the simulation model. The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-022-00422-0     

Simulation of growth dynamics in atomic layer deposition. Part II. Polycrystalline films from cubic crystallites

The growth dynamics of polycrystalline thin films by the atomic layer deposition (ALD) technique has been simulated for randomly oriented and randomly positioned seed objects. Cubic crystals with the shape of cubes, octahedra, and truncated cubes have been used to exemplify the dynamics of polycrystalline growth of films with columnar structures. We have reproduced the non-linear growth in the initial stages of ALD preparation of polycrystalline films according to type-2 substrate-inhibited growth. The dependences of topography roughness, surface object density, and selection of angles on terminating surfaces on the film thickness are demonstrated. The topography and cross sections of the simulated films are also shown for the different crystal shapes considered. Means to control the topography to obtain either smooth or rough films are discussed. A possible reduction of surface roughness by the use of different types of precursors is exemplified for growth of crystal objects combining cube and octahedron shapes.