摘要
单点金刚石车削(SPDT)硫化锌(ZnS)晶体时,切削参数对表面质量有显著影响。因此,为获得高质量的ZnS晶体表面,选取主轴转速、进给速度、切削深度为影响表面质量的工艺参数,采用正交实验方法对ZnS晶体进行了车削实验。以表面粗糙度(Ra)值和表面形貌特征作为表征表面质量优劣的指标,采用轮廓仪和扫描电镜(SEM)对加工表面质量进行了检测。得到ZnS晶体车削的最佳切削参数以及主轴转速、进给速度和切削深度对Ra和表面形貌的影响规律。结果表明:进给速度对Ra的影响最大,其贡献率达到61.38%,主轴转速和切削深度的贡献率分别为19.20%和4.02%,较高的主轴转速、较低的进给速度和切削深度能够抑制ZnS晶体表面发生脆性断裂,有利于高质量表面的生成。在最佳加工参数,即主轴转速3800 r·min^(-1),进给速度2 mm·min^(-1),切削深度5μm的条件下对ZnS晶体进行切削,可以获得Ra为2.3 nm的高质量ZnS平面光学元件。
Zinc sulfide crystal (ZnS) material has become the key material in the field of infrared imaging and infrared guidance technology due to its excellent optical and mechanical properties,such as long-wave infrared windows,fairings and optical lens components.Correspondingly,it comes higher and higher requirements for the surface quality of ZnS crystal.However,it is difficult to obtain high quality surface because of its high brittleness,softness and anisotropy.Single point diamond turning (SPDT) technology has been widely used in the mechanical processing of ZnS crystal.However,it is difficult to control the surface quality of turning due to the influence of cuttingconditions,infrared material properties,tool parameters and other factors.Therefore,to obtain a high-quality ZnS crystal surface,the spindle speed,feed speed and cutting depth were selected as the process parameters affecting the surface quality,and the turning experiment of ZnS crystal was carried out by orthogonal experiment method.The surface roughness (Ra) and surface topography were used as indicators to characterize the surface quality.Turning experiment was carried out on the single point diamond precision lathe (Innolite 600) and the quality of the processed surface was detected by profiler and scanning electron microscope (SEM).The optimum parameter combination of ZnS crystal turning and the influence of cutting conditions (spindle speed,feed speed and cutting depth) on surface quality (roughness and topography) were obtained.From the turning experiments of ZnS crystal,the following main conclusions could be obtained:(1) The feed speed had the greatest influence on Ra,and its contribution rate reached 61.38%.The contribution rates of spindle speed and cutting depth were 19.20%and 4.02%respectively.Higher spindle speed,lower feed speed and cutting depth had conducive to the generation of high-quality surfaces,this was because it could inhibit brittle fracture on the surface of ZnS crystals.(2) There were three main removal mechanisms for ZnS crystals:plastic deformation,brittle fracture and the simultaneous existence of two removal methods.As the spindle speed decreasedand the feed speed increased,brittle fracture appeared on the surface of ZnS crystal,and the increase of cutting depth would lead to the appearance of breaking points on machined surface.Therefore,the conditions for plastic removal of ZnS crystal were higherspindle speed,lower feed speed and cutting depth.(3) Through the orthogonal experiment of ZnS crystal turning,the best combination of cutting conditionswas finally determined as follows:spindle speed was 3800 r·min^(-1),feed speed was 2 mm·min^(-1),and cutting depth was 5μm.A verification experiment was carried out.The processed surface of ZnS crystal was transparent,the surface was relatively smooth under SEM and material removal mechanism was plastic deformation,and Rareached 2.3 nm.Due to the wide application of ZnS crystals in optical field,it was very important to achieve high-quality surface processing of ZnS crystal optical components.In this study,the optimization experiment of ZnS crystal processing was carried out by orthogonal experiment,and the optimal cuttingconditions for ZnS crystal processing were obtained.In the future,laser-assisted machining (LAM) technology would be combined to remove surface defect during ZnS crystal processing.
作者
郭彦军
杨晓京
李茂忠
康杰
张万清
谢启明
Guo Yanjun;Yang Xiaojing;Li Maozhong;Kang Jie;Zhang Wanqing;Xie Qiming(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;Yunnan KIR0 Photonics Co.,Ltd,Kunming 650217,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2023年第2期315-321,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51765027)
昆明理工大学分析测试基金资助项目(2020P20191103002)资助。
