共查询到20条相似文献,搜索用时 468 毫秒
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振动切削与加工表面完整性 总被引:1,自引:1,他引:0
本文从现代工业对零件加工表面完整性的要求入手,分析了零件加工表面完整性的影响因素及改善措施,提出振动切削加工方法是改善零件加工表面完整性的一种行之有效的加工方法。 相似文献
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超光滑表面加工技术研究进展 总被引:2,自引:0,他引:2
针对如何高效稳定地获得粗糙度值小、少无亚表面损伤、低成本的超光滑表面的问题,分析了原子级超光滑表面加工技术的加工原理,详细阐述了几类非接触式抛光方法的加工原理及国内外最新研究进展,并着重论述了声悬浮抛光和磨料水射流抛光的研究现状。接着,在此基础上对这几类加工方法各方面的优缺点进行了对比总结。最后,针对目前超光滑表面加工技术存在的不足,指出了超光滑表面加工技术有待进一步研究的方向。研究结果表明,采用非接触式的抛光方法,对加工过程加以合理的控制,可大大降低工件表面粗糙度,改善亚表面的损伤情况;目前非接触式抛光普遍对抛光设备精度要求较高,减少加工成本是超光滑表面加工技术进行大规模推广的迫切要求。 相似文献
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超精密磨削加工表面形貌建模与仿真方法宰 总被引:4,自引:2,他引:2
超精密磨削技术是实现微/纳米加工的主要手段.系统深入研究超精密磨削过程的机理,洞悉磨削加工表面生成的内涵,成为超精密磨削加工技术的重要研究内容之一.提出一种新型的超精密磨削加工表面生成方法.基于Jobnson变换和线性滤波技术,给出砂轮表面形貌数字生成方法.该砂轮表面数值生成方法克服了利用试验测量砂轮表面形貌所得数据而带来的误差,提高了磨削加工表面仿真分析的准确性.根据磨削运动学,建立磨粒运动轨迹方程、相互干涉条件和有效磨粒确定方法.据此,给出超精密磨削加工表面生成算法.通过数值计算生成不同统计学特征的砂轮形貌,并得到不同加工参数下磨削表面的表面形貌,仿真结果验证了所给算法的正确性和有效性. 相似文献
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工件在机械加工过程中,都会在加工表面留下反映其加工方式特点的表面纹理,通过对不同表面纹理的支承长度率及其曲线进行分析比较,为合理地选择工件加工工艺提供了依据. 相似文献
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研究了基于电火花机械复合磨削技术加工的反应烧结碳化硅(RB-SiC)陶瓷的表面特征。用电火花机械复合磨削(EDDG)、电火花磨削(EDG)以及普通磨削(CG)三种方法加工RB-SiC陶瓷,并采用激光共聚焦显微镜和扫描电子显微镜对加工后的SiC陶瓷的表面粗糙度、表面形貌及微观裂纹进行测量和对比试验,获得了RB-SiC陶瓷的EDDG加工特性。实验显示:EDDG加工的RB-SiC陶瓷的表面粗糙度优于EDG加工的表面粗糙度,为0.214 9μm,但比CG加工的表面粗糙度0.195 6μm略差。对加工后的SiC陶瓷表面形貌观察显示,传统磨削加工后的表面存在明显划痕,EDG加工表面主要由放电凹坑组成,而EDDG加工表面同时存在放电凹坑和磨削划痕;另外,传统磨削表面也存在磨削裂纹和晶界裂纹,但EDG加工后的表面只存在热裂纹,而EDDG加工后的表面存在磨削裂纹和热裂纹,不过热裂纹可以用金刚石磨粒磨削去除。对比实验显示RB-SiC陶瓷的EDDG加工与EDG和CG加工获得了不同的表面特征。 相似文献
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秦旭平 《机械工程与自动化》2000,(2)
为了拓展圆弧齿轮的应用范围 ,本文介绍了渗碳硬化双圆弧齿轮超硬加工技术。应用这项技术加工的硬齿面双圆弧齿轮 ,其承载能力与相同规格的硬齿面渐开线齿轮相当 相似文献
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空间RB-SiC反射镜的表面离子辅助镀硅改性技术 总被引:3,自引:0,他引:3
针对空间用RB-SiC材料由Si\SiC两相结构引起的光学表面缺陷问题,提出了表面离子辅助沉积(IAD)硅膜的改性新方案以优化RB-SiC光学表面反射率。对厚度为10µm的IAD-Si改性层的主要性能研究显示:IAD-Si膜层为非结晶结构,能够提供较好的抛光表面,在77K-673K的热冲击下膜层稳定性良好。以Si膜的抛光机理为依据对IAD-Si改性层进行了大量抛光工艺实验和表面质量测试,给出了关键的抛光工艺参数和实验结果。通过表面IAD-Si改性及本文提出的改性层超精加工技术能够在反射镜表面得到面形精度的RMS值低于1/20λ(λ=632.8nm)且表面粗糙度的RMS值低于0.5nm的超光滑表面;与改性前相比,反射镜改性层抛光表面在360-1100 nm 波段的反射率提高了4.5%以上。 相似文献
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Intersections and discontinuities commonly arise in surface modeling and cause problems in downstream operations.Local geometry repair,such as cover holes or replace bad surfaces by adding new surface patches for dealing with inconsistencies among the confluent region,where multiple surfaces meet,is a common technique used in CAD model repair and reverse engineering.However,local geometry repair destroys the topology of original CAD model and increases the number of surface patches needed for freeform surface shape modeling.Consequently,a topology recovery technique dealing with complex freeform surface model after local geometry repair is proposed.Firstly,construct the curve network which determine the geometry and topology properties of recovery freeform surface model;secondly,apply freeform surface fitting method to create B-spline surface patches to recover the topology of trimmed ones.Corresponding to the two levels of enforcing boundary conditions on a B-spline surface,two solution schemes are presented respectively.In the first solution scheme,non-constrained B-spline surface fitting method is utilized to piecewise recover trimmed confluent surface patches and then employs global beautification technique to smoothly stitch the recovery surface patches.In the other solution scheme,constrained B-spline surface fitting technique based on discretization of boundary conditions is directly applied to recover topology of surface model after local geometry repair while achieving G 1 continuity simultaneously.The presented two different schemes are applied to the consistent surface model,which consists of five trimmed confluent surface patches and a local consistent surface patch,and a machine cover model,respectively.The application results show that our topology recovery technique meets shape-preserving and G 1 continuity requirements in reverse engineering.This research converts the problem of topology recovery for consistent surface model to the problem of constructing G 1 patches from a given curve network,and provides a new idea to model repairing study. 相似文献
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螺旋曲面零件是螺旋类机械的重要组成部分,其精度影响着螺杆机械的性能。研究了螺旋曲面盘铣刀的铣削原理,通过与传统的成形铣削对比,建立了刀具与工件的相对位置及坐标系,研究了工件与刀具的空间啮合条件,为进一步研究高精度复杂螺旋曲面加工技术奠定了理论基础。 相似文献
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This paper describes a spatial measurement technique to measure the free surface of natural fluid flows in laboratory applications. This effective solution is based on “Structure-from- Motion/Multi-view Stereo” (SfM-MVS) photogrammetry and is capable of reconstructing water surface morphology, both at an instant and with a high spatial resolution. The efficiency and accuracy of the method is dependent upon the acquisition of high quality imagery (i.e. sharply focussed, no motion blur) with appropriate multi-frame camera coverage and configuration, and data processing must utilise appropriate camera calibration data. The potential of the technique for developing hydraulic understanding is demonstrated using two contrasting approaches. First, the water surface behind a living vegetation element is analysed along a single transect. Second, the full three-dimensional characteristics of the captured water surfaces are examined using statistical methods which demonstrate surface dissimilarity between vegetated and non-vegetated cases. The technique is transferable to real-world field sites. 相似文献