共查询到18条相似文献,搜索用时 312 毫秒
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针对KDP在SPDT切削过程中容易产生凹坑、划痕、裂纹等表面缺陷问题,提出利用热激励的方式增大KDP晶体塑性切削域深度,降低各向异性、机床运动误差、环境振动等因素对加工过程的影响,进而提高SPDT切削加工过程稳定性的方法。通过纳米压痕试验获得了KDP晶体表面在不同温度状态下的硬度和脆塑性转变深度变化规律,并在SPDT机床上采用金刚石刀具开展了KDP晶体飞切划痕实验,进一步验证了适当提高KDP晶体温度可以增大KDP晶体脆塑性转变临界切削深度。在此基础上,对KDP晶体开展了不同温度状态下的切削实验,实验结果表明在相同工艺参数下,随着温度的升高,表面粗糙度Sa值从3.2nm降低至1.6nm。 相似文献
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《机械设计与制造》2017,(1)
针对KDP晶体超精密加工过程中出现的表面波纹度和粗糙度问题,采用二次通用回归旋转组合优化设计法及单点金刚石飞刀切削(SPDT)技术,对KDP晶体进行切削实验,对加工过程进行在线监测,利用多因素交互作用分析KDP晶体表面波纹度和粗糙度的影响规律。最后利用偏最小二乘法及lingo软件获得最佳加工工艺参数组合,即当刀具圆弧半径为9mm;转速为800 r/min;进给量为9.184μm/r;背吃刀量为21μm时,加工出KDP晶体的表面波纹度值为0.020μm,表面粗糙度值为0.017μm,对后续能够加工出更大口径(400×400)mm的高质量KDP晶体以满足航空航天领域应用具有重要的实际意义。 相似文献
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KDP晶体光学零件超精密加工技术研究的新进展 总被引:11,自引:0,他引:11
KDP晶体作为优质的非线性光学材料 ,被广泛的应用于激光非线性光学领域。由于大型KDP晶体具有一系列不利于光学加工的特点 ,因此被公认为是最难加工的光学零件。本文概述了KDP晶体超精密磨削和磁流变抛光的加工方法 ,阐述了KDP晶体光学零件单点金刚石加工技术的研究现状 ,并详细地分析了单点金刚石切削加工时机床精度、加工工艺参数、装夹变形、晶格方向变化、金刚石刀具几何参数、冷却液等对加工表面质量 (平面度、表面粗糙度、小尺度波纹等 )的影响 相似文献
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光学玻璃的精密加工技术 总被引:1,自引:0,他引:1
光学玻璃作为一种典型的脆硬材料,采用普通的加工方法难以进行高效精密加工。本文介绍了光学玻璃的高效精密特种加工技术,对ELID法、激光加工、超声磨削以及精密铣削的最新研究进展进行了综述。采用ELID技术,通过控制加工工艺参数,使砂轮单个磨粒的最大切削深度小于脆性材料的临界切削厚度,实现了脆性材料的塑性加工,并得到精密光滑的表面;在加工非球曲面时,可使零件的精加工抛光量降到最低。最新激光加工技术通过增加预热激光束,极大降低已加工表面的热应力及拉伸应力,使得加工质量有了大幅提高。超声波磨削加工不仅改善了表面完整性,而且提高了加工效率,通过选用适当的刀具和工艺参数,使被加工工件表面粗糙度值比普通磨削降低了30%~40%。光学玻璃精密铣削技术通过优化刀具、加工方式及工艺参数,可提高加工质量和效率、降低加工成本。 相似文献
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通过响应面分析法(RSM)对超声振动辅助金刚石线锯切割SiC单晶体的工艺参数进行分析和优化。采用中心组合设计实验,考察线锯速度、工件进给速度、工件转速和超声波振幅这4个因素对SiC单晶片表面粗糙度值的影响,建立了SiC单晶片表面粗糙度的响应模型,进行响应面分析,采用满意度函数(DFM)确定了切割SiC单晶体的最佳工艺参数,验证试验表明该模型能实现相应的硬脆材料切割过程的表面粗糙度预测。 相似文献
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为在曲面精加工中获得理想的表面粗糙度,通过分析表面粗糙度的形成机理,建立了粗糙度与走刀行距、进给率关系的数学模型;通过实验,建立了高速曲面铣削时粗糙度与加工倾角、主运动线速度关系的图谱,实现了在生产过程中按照加工目标的表面粗糙度确定相应的走刀行距、进给率、加工倾角、主运动线速度等加工参数.研究结果表明,该研究对提高加工... 相似文献
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Micro-milling is a promising approach to repair the micro-defects on the surface of KH2PO4 (KDP) crystal. The geometrical parameters of micro ball end mill will greatly influence the repairing process as a result of the soft brittle properties of KDP crystal. Two types of double-edged micro ball end mills were designed and a three-dimensional finite element (FE) model was established to simulate the micro milling process of KDP crystal, which was validated by the milling experiments. The rake angle of −45°, the relief angle of 45° and the cutting edge radius of 1.5–2 μm were suggested to be the optimal geometrical parameters, whereas the rake angle of −25° and the relief angle of 9° were optimal just for micro ball end mill of Type I, the configuration with the rake angles ranging from 0° to 35°, by fully considering the cutting force, and the stress–strain distribution over the entire tool and the cutting zone in the simulation. Moreover, the micro polycrystalline diamond (PCD) ball end mills adopting the obtained optimal parameters were fabricated by wire electro-discharge machining (WEDM) and grinding techniques, with the average surface roughness Ra of tool rake face and tool flank face ∼0.10 μm, and the cutting edge radius of the tool ∼1.6 μm. The influence of tool's geometrical parameters on the finished surface quality was verified by the cutting experiments, and the tool with symmetric structure was found to have a better cutting performance. The repairing outlines with Ra of 31.3 nm were processed by the self-fabricated tool, which could successfully hold the growth of unstable damage sites on KDP crystal. 相似文献
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High-quality pure-nickel microstructures, which are characterized with multiple superior machining indicators, including machining homogeneity, machining surface roughness, and machining round edge, are now highly anticipated in the field of micromachines and microsystems. However, according to the published studies, a gap remains in achieving high-quality machining. In this paper, wire electrochemical micromachining (WECMM) is proposed for machining high-quality pure-nickel microstructures focusing on different machining indicators. The appropriate electrolyte is selected by combining analysis of the electrochemical characteristics and machining experiments involving microslits of pure nickel. In contrast with previous studies that usually focused on the machining homogeneity or machining surface roughness of the machining results, the effects of several critical machining parameters on the machining homogeneity, machining surface roughness, and machining rounded edge are studied comprehensively, and the relative results for different machining indicators are also revealed. Finally, the combinations of process parameters for manufacturing high-quality pure-nickel microstructures focusing on different machining indicators are identified, and corresponding high-quality pure-nickel microstructures are fabricated. 相似文献
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Haofeng Chen Yifan Dai Ziwen Zheng Hang Gao Xiaoping Li 《Machining Science and Technology》2013,17(2):231-242
In order to investigate the influence of material anisotropy in ductile cutting of Potassium Dihydrogen Phosphate (KDP) crystals, experiments of face cutting of (001) plane of KDP crystals are carried out by using an ultra-precision lathe with a single point diamond tool. The cutting forces, surface finish, and surface roughness in all crystallographic orientations of the machined surface are measured, and a power spectrum analysis method is used to reveal the cutting force patterns. The experimental results show that the cutting forces and surface roughness vary greatly with different crystallographic orientations of KDP crystal, and that amplitude variation of cutting forces and surface finish is closely related with the cutting parameter of the maximum undeformed chip thickness. With the maximum undeformed chip thickness below 30 nm, the amplitude variation of cutting force and surface finish is minimized, and a super-smooth surface with consistent surface finish in all the crystallographic orientations can be achieved. The surface roughness is 2.698 nm (Ra) measured by Atomic Force Microscope (AFM). These findings provide criteria for achieving a large-scale KDP crystal with consistent super-smooth surface using ductile cutting technology. 相似文献
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Development of surface roughness optimisation and prediction for the process of wire electro-discharge grinding 总被引:1,自引:1,他引:0
A. Rees E. Brousseau S. S. Dimov S. Bigot C. A. Griffiths 《The International Journal of Advanced Manufacturing Technology》2013,64(9-12):1395-1410
This paper investigates the technological capabilities of a hybrid micro machining process for performing wire electro-discharge grinding (WEDG). In particular, micro wire electrical discharge machining (μWEDM) is employed in combination with a rotating submergible spindle to perform WEDG. In this research, first a machining strategy for workpiece preparation is presented. Then, the effects of different machining setup parameters on the achievable surface finish after WEDG are investigated. In particular, an experimental study was conducted to identify the most statistically significant setup parameters for performing the main cut that affect the resulting surface quality. A signal-to-noise (S/N) ratio analysis was conducted to optimise the technological parameters for performing WEDG. By modifying the discharge energy for main cuts when performing WEDG surface finish comparable to that of μWEDM can be achieved. In addition, a simple and cost-effective method for on-the-machine estimation of resulting surface roughness is proposed. Especially, by applying inductive learning a surface roughness prediction model for WEDG can be generate based on data acquired by monitoring on-line the process. 相似文献