期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
基于近红外光谱的材料粗糙度变化检测研究
1
作者 鲁芬 郁伯铭 《激光杂志》 CAS 北大核心 2022年第5期70-74,共5页
为提高材料粗糙度变化检测的准确性,提出了一种基于近红外光谱的材料粗糙度变化检测方法。测量热红外偏振度,采用主成分分析方法降维处理。利用双温方程对光子照射到材料表面的条件下光子与电子及离子的能量转化情况分析,以对基体材料... 为提高材料粗糙度变化检测的准确性,提出了一种基于近红外光谱的材料粗糙度变化检测方法。测量热红外偏振度,采用主成分分析方法降维处理。利用双温方程对光子照射到材料表面的条件下光子与电子及离子的能量转化情况分析,以对基体材料吸收率计算,等效处理材料表面粗糙度。通过双向分布函数构建粗糙度计算模型,完成材料粗糙度变化检测。实验将检测准确性与检测时间作为对比指标,结果表明,此次研究的检测方法有效提高了检测的准确度,平均为91%,并减少了检测的时间,平均为2.2 min。 展开更多
关键词 近红外光谱 材料粗糙度 变化检测 等效处理
下载PDF
基于计量学的线边缘粗糙度定义 被引量:4
2
作者 赵学增 李洪波 +2 位作者 褚巍 肖增文 李宁 《机械工程学报》 EI CAS CSCD 北大核心 2007年第1期214-218,共5页
对目前线边缘粗糙度(Line edge roughness,LER)的研究进行了分类,区分线宽变化率、线的边缘粗糙度和侧墙(边缘)粗糙度的物理本质。重新给出一个LER定义,定义LER是由加工工艺和材料本身结构引起的刻线侧墙的表面形貌微观不规则程度,并分... 对目前线边缘粗糙度(Line edge roughness,LER)的研究进行了分类,区分线宽变化率、线的边缘粗糙度和侧墙(边缘)粗糙度的物理本质。重新给出一个LER定义,定义LER是由加工工艺和材料本身结构引起的刻线侧墙的表面形貌微观不规则程度,并分析给出定义的合理性。给出该定义和ITRS定义间的换算关系。结合刻线的加工过程主要发生在刻线的边缘表面,且该加工过程发生于深纳米尺度,给出一种基于原子尺度的LER计量模型,在该模型中分离了材料本质粗糙度。 展开更多
关键词 纳米计量 临界尺寸 线边缘粗糙度 材料本质粗糙度 扫描电子显微镜(SEM) 原子力显微镜(AFM)
下载PDF
椭偏法测量表面微粗糙合金钢材料的光学常数研究
3
作者 武颖丽 吴振森 《应用光学》 CAS CSCD 2008年第4期610-613,共4页
采用椭偏法测量入射光波长为0.632μm,入射角为50°~85°时合金钢的光学常数。考虑材料表面的粗糙度,用Ohlidal—Lukes理论对所测光学常数值进行了修正,发现椭偏参量的修正量随入射角增大而增大。结果表明,测量入射角在50... 采用椭偏法测量入射光波长为0.632μm,入射角为50°~85°时合金钢的光学常数。考虑材料表面的粗糙度,用Ohlidal—Lukes理论对所测光学常数值进行了修正,发现椭偏参量的修正量随入射角增大而增大。结果表明,测量入射角在50°~70°范围内测量值与修正后计算结果基本一致,在70°~85°范围内测量值与修正后的计算结果差距较大。因此,用椭偏法测量合金钢光学常数时使入射角小于70°,测量结果会更加准确。 展开更多
关键词 椭偏法 光学常数 材料表面粗糙度
下载PDF
MACHINING OF METAL MATRIX COMPOSITES 被引量:3
4
作者 徐九华 左敦稳 杨明达 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期161-167,共7页
Two types of aluminium-based composites reinforced respectively with 20 vol short fibre alumina and with a hybrid of 15 vol SiC particle and 5 vol short alumina fibre are machined with different tool materials:cemente... Two types of aluminium-based composites reinforced respectively with 20 vol short fibre alumina and with a hybrid of 15 vol SiC particle and 5 vol short alumina fibre are machined with different tool materials:cemented carbide,ceramic,cubic boron nitride(CBN)and polycrystalline diamond(PCD).The analysis on tool wear shows that the various tool materials exhibite different tool wear behaviours,and the tool wear mechanisma are discussed.Apparently,PCD tools do not necessarily guarantee dimensional stability but they can provide the most economic means for machining all sorts of composites.Consequently,a suitable tool material is suggested for machining each metal matrix composite(MMC) from the standpoints of tool wear and machined surface finish. 展开更多
关键词 MACHINING cutting force surface roughness metal matrix composite tool wear
下载PDF
Effect of laser textured surface with different patterns on tribological characteristics of bearing material AISI 52100 被引量:8
5
作者 PAUL JOSHUA S DINESH BABU P 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第8期2210-2219,共10页
Chrome steels are used in bearings since they possess high strength and wear resistance.However,when those parts are in service,failure happens due to sliding friction before the lifetime.To improve the durability of ... Chrome steels are used in bearings since they possess high strength and wear resistance.However,when those parts are in service,failure happens due to sliding friction before the lifetime.To improve the durability of the American Iron and Steel Institute(AISI)52100 chromium steel,in this work,the effect of laser surface texturing(LST)was analyzed.With the different patterns of circle and ellipse comparing with the untextured samples,the wear behavior was investigated using the pin-on-disc tribometer.The lubricant used for wear analysis is semisolid lithium grease National Lubricating Grease Institute lubricant(SKF NLGI-3).Sliding wear analysis was conducted at different loads of 10 N,30 N and 50 N for the sliding speed of 750 r/min and 1400 r/min.The wear morphology was analyzed using a scanning electron microscope(SEM).The roughness of the samples was found using a white light interferometer.The effect of different patterns like circle and ellipse,alter the friction and wear properties of chromium alloy was observed compared with the untextured samples.LST shows considerable reduction in friction and wear for ellipsoidal pattern compared with the circular pattern because of wear debris and lubricant getting trapped. 展开更多
关键词 laser surface micro texturing AISI52100 3D surface roughness WEAR scanning electron microscopy
下载PDF
A 3D evaluation method of cutting surface topography of carbon/carbon(C/C) composite 被引量:1
6
作者 周鹏 Zhao Fuling 《High Technology Letters》 EI CAS 2010年第4期366-372,共7页
This paper aims to establish a 3D evaluation method for cutting surface topography of C/C composites. The cutting surface is measured by Talyscan 150, using 3D non-contact measurement. By evaluating 2D and 3D roughnes... This paper aims to establish a 3D evaluation method for cutting surface topography of C/C composites. The cutting surface is measured by Talyscan 150, using 3D non-contact measurement. By evaluating 2D and 3D roughness of C/C composite and Duralumin, the 2D evaluation method of the cutting surface topography of C/C composite loses a lot of information, and the characteristics of the surface topography of C/C composite can be comprehensively and authentically evaluated only by the 3D evaluation method. Furthermore, 3D amplitude and spatial parameters are adopted to evaluate the surface and the results show that: the topography of the C/C composite is anisotropy and there are no obvious feeding textures but abrupt peaks and valleys on surface of the C/C composite, which indicates that the machining mecha- nism is different from that of the metal. In conclusion, The C/C composite surface is evaluated using a 3D evaluation method, the roughness error is small, and the unique topography characteristics earl be au- thentically evaluated. 展开更多
关键词 C/C composite surface topography 3D evaluation method
下载PDF
Wire electric discharge machining characteristics of titanium nickel shape memory alloy
7
作者 M.MANJAIAH S.NARENDRANATH +1 位作者 S.BASAVARAJAPPA V.N.GAITONDE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第10期3201-3209,共9页
Ti Ni shape memory alloys(SMAs) have been normally used as the competent elements in large part of the industries due to outstanding properties, such as super elasticity and shape memory effects. However, traditiona... Ti Ni shape memory alloys(SMAs) have been normally used as the competent elements in large part of the industries due to outstanding properties, such as super elasticity and shape memory effects. However, traditional machining of SMAs is quite complex due to these properties. Hence, the wire electric discharge machining(WEDM) characteristics of Ti Ni SMA was studied. The experiments were planned as per L27 orthogonal array to minimize the experiments, each experiment was performed under different conditions of pulse duration, pulse off time, servo voltage, flushing pressure and wire speed. A multi-response optimization method using Taguchi design with utility concept has been proposed for simultaneous optimization. The analysis of means(ANOM) and analysis of variance(ANOVA) on signal to noise(S/N) ratio were performed for determining the optimal parameter levels. Taguchi analysis reveals that a combination of 1 μs pulse duration, 3.8 μs pulse off time, 40 V servo voltage, 1.8×105 Pa flushing pressure and 8 m/min wire speed is beneficial for simultaneously maximizing the material removal rate(MRR) and minimizing the surface roughness. The optimization results of WEDM of Ti Ni SMA also indicate that pulse duration significantly affects the material removal rate and surface roughness. The discharged craters, micro cracks and recast layer were observed on the machined surface at large pulse duration. 展开更多
关键词 TiNi shape memory alloy wire electric discharge machining(WEDM) surface roughness material removal rate surface morphology
下载PDF
The Study of Resistance of Cement Composites against Microbial Attack
8
作者 Estokova Adriana Ondrejka Harbulakova Vlasta +2 位作者 Luptakova Alena Prascakova Maria Stevulova Nadezda 《Journal of Civil Engineering and Architecture》 2011年第6期555-561,共7页
The start and the course of bio-corrosion are conditioned by many factors which include biological effects like the influence of vegetation and microorganisms causing the deterioration of materials. The influence of b... The start and the course of bio-corrosion are conditioned by many factors which include biological effects like the influence of vegetation and microorganisms causing the deterioration of materials. The influence of bacteria causing the deterioration of concrete has been linked to the generation of biogenic sulphuric and nitric acids which originate in corrosion process by dissolution of calcium containing minerals from the concrete matrices. This paper primarily focuses on the investigation of influence of sulphur-oxidising bacteria Acidithiobacillus thiooxidans and sulphate-reducing bacteria Desulfovibrio desulfuricans at the resistance degree of cement composites. Various concrete composites with 5% addition of black coal fly ash as cement replacement as well as the reference samples without coal fly ash addition were studied in the experiments environments of sewage system proceeded during 90 days. The The laboratory experiments as well as experiments in situ in real corrosion was manifested by surface changes and weight changes of cement composites samples as well as changes in pH values of leachates. Considerable surface changes were detected in all investigated samples by microscopic methods. Crystals precipitated on concrete samples surface were identified by EDX as mixture of gypsum and ettringite. The roughness increases of surface of cement microscopy. composites were determined by confocal laser scanning 展开更多
关键词 Concrete MIC BACTERIA BIOCORROSION biodeterioration.
下载PDF
Choice of reference surfaces for machined surface roughness in milling of SiC_p/Al composites 被引量:4
9
作者 王阳俊 黄海波 +1 位作者 陈立国 孙立宁 《Journal of Central South University》 SCIE EI CAS 2014年第11期4150-4156,共7页
In order to choose the appropriate reference surface on the machined surface roughness of Si Cp/Al composites, the cutting experiments of Si Cp/Al composites were carried out, and the machined surface topography was m... In order to choose the appropriate reference surface on the machined surface roughness of Si Cp/Al composites, the cutting experiments of Si Cp/Al composites were carried out, and the machined surface topography was measured by OLS3000 Confocal laser scanning microscope. The 3D measured data of machined surface topography were analyzed by the area power spectrum density. The result shows that the texture of machined surface topography in milling of Si Cp/Al composites is almost isotropic. This is the reason that the values of Rq at different locations on the same machined surface are obviously different. Through the comparison of performance of different filtering methods, the robust least squares reference surface can be used to extract the surface roughness of SiC p/Al composites effectively. 展开更多
关键词 SiCp/Al composites surface topography milling filtering method power spectrum density
下载PDF
Surface Roughness of Material Processing during Milling Process
10
作者 Lulzim Bala Afrim Gjelaj +1 位作者 Avdyl Bunjaku Avdi Salihu 《Journal of Mechanics Engineering and Automation》 2012年第10期601-605,共5页
To realize full automation in machining process, Computer Numerically Controlled (CNC) machine tools have been implemented during the past decades. The CNC machine tools require less operator input, provide greater ... To realize full automation in machining process, Computer Numerically Controlled (CNC) machine tools have been implemented during the past decades. The CNC machine tools require less operator input, provide greater improvements in productivity, and increase the quality of the machined part. End milling is the most common metal removal operation encountered. It is widely used to mate with other part in die, aerospace, automotive, and machinery design as well as in manufacturing industries. Surface roughness is an important measure of the technological quality of a product and a factor that greatly influences manufacturing cost. The quality of the surface plays a very important role in the performance of milling as a good-quality milled surface significantly improves fatigue strength, corrosion resistance, or creep life. Consequently, the desired surface roughness value is usually specified for an individual part, and specific processes are selected in order to achieve the specified finish. Purpose of the study is to develop a technique to predict a surface roughness of the part to be machined according to technological parameters. Such technique could be achieved by making mathematical model of machining. In this study as machining process the milling process is chosen, especially for end milling operation. Additionally to the study, one of the key factors, which differ from similar studies, is that as surface parameters the 2D, 3D surface parameters are used. In this study, all the surface parameters are expressed as 2D, 3D parameters. The 2D, 3D surface parameters give more precise figure of the surface; therefore it is possible to evaluate the surface parameters more precisely according to technological parameters. The result of the study, mathematical model of end-milling is achieved and qualitative analysis is maintained. Achieved model could help technologists to understand more completely the process of forming surface roughness. 展开更多
关键词 Milling machine surface roughness 2D and 3D surface parameters.
下载PDF
Surface effects of liquid metal amoeba 被引量:2
11
作者 Liang Hu Jing Li +1 位作者 Jianbo Tang Jing Liu 《Science Bulletin》 SCIE EI CAS CSCD 2017年第10期700-706,共7页
Liquid metals(LM) such as eutectic gallium-indium and gallium-indium-tin are important functional liquid-state metal materials with many unique properties, which have attracted wide attentions especially from soft rob... Liquid metals(LM) such as eutectic gallium-indium and gallium-indium-tin are important functional liquid-state metal materials with many unique properties, which have attracted wide attentions especially from soft robot area. Recently the amoeba-like transformations of LM on the graphite surface are discovered, which present a promising future for the design and assemble of self-fueled actuators with dendritically deformable body. It appears that the surface tension of the LM can be significantly reduced when it contacts graphite surface in alkaline solution. Clearly, the specific surface should play a vital role in inducing these intriguing behaviors, which is valuable and inspiring in soft robot design. However, the information regarding varied materials functions underlying these behaviors remains unknown. To explore the generalized effects of surface materials in those intriguing behavior, several materials including glass, graphite, nickel and copper oxides(CuO) were comparatively investigated as substrate surfaces.Important results were obtained that only LM amoeba transformations were observed on graphite and CuO surfaces. In order to identify the proper surface condition for LM transformation, the intrinsic properties of substrate surfaces, such as the surface charge and roughness, as well as the specific interaction with LM like wetting behavior and mutual locomotion etc., were characterized. The integrated results revealed that LM droplet appears more likely to deform on surfaces with higher positive surface charge density, higher roughness and less bubble generation on them. In addition, another surface material,CuOx, is identified to own similar ability to graphite, which is valuable in achieving amoeba-like transformation. Moreover, this study offers a fundamental understanding of the surface properties in realizing LM amoeba transformations, which would shed light on packing and structure design of liquid metal-based soft device within multi-material system. 展开更多
关键词 Surface effect Liquid metal amoeba Surface tension Substrate materials
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部