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Evaluation Of Diamond Wear Characteristics And Its Impact On Material Processing

Posted on:2021-01-01Degree:MasterType:Thesis
Country:ChinaCandidate:Y DengFull Text:PDF
GTID:2381330611962332Subject:Mechanical engineering
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As the hardest substance in nature,diamond is used as an abrasive in cutting tools and grinding and polishing tools due to its excellent mechanical properties.It has a wide range of applications in precision and ultra-precision machining,especially stone,crystalline silicon,ceramics,concrete,Hard and brittle materials such as sapphire,using diamond tools is still an important processing method.Hard and brittle materials have the characteristics of high strength,high hardness,high brittleness,wear resistance and corrosion resistance,low density and low expansion coefficient,and good chemical stability,which are very different from metal materials.When processing hard and brittle materials with diamond tools,diamond tools will inevitably wear due to severe friction and high temperature.The impact of different degrees of diamond wear on the processing process and processing results is also different: on the one hand,wear The form of interaction between the diamond and the workpiece changes during processing,which affects the removal process of the workpiece material;on the other hand,the wear of diamond also affects the service life of the diamond tool.It is of great significance to study the influence of diamond tools in the state of wear on the processing of hard and brittle materials for the rational selection of process parameters,improve the performance of diamond tools when processing hard and brittle materials,and improve the processing quality of hard and brittle materials.As a simplified form of abrasive grain processing,the single diamond abrasive grain scratch experiment is used by many scholars to study the processing process of materials and explore the removal mechanism of materials.In this paper,starting with the single diamond abrasive grain scratching experiment,a single abrasive grain scratching experiment is performed on the SiC ceramic material with the diamond indenter in the worn state,and digital image processing technology is introduced to digitally detect the worn diamond image captured Image processing,through related mathematical calculations,to obtain the corresponding wear of diamond,and explore the impact of these wear on the processing of SiC ceramics.The main work content and conclusion of this article are as follows:(1)In view of the disadvantages of low manual detection efficiency and subjective errors,the subject proposes to use digital image processing technology to analyze and process the relevant diamond images to obtain information such as diamond shape characteristics;(2)The wear height,wear area,wear volume,wear sharpness and other quantities are proposed to quantitatively characterize diamond wear,and correlation analysis is carried out.Finally,the wear sharpness is selected as the characterization amount of diamond wear;(3)A series of diamond abrasive wear experiments was conducted,finally,the mechanical wear method was used to wear the diamond indenter used in the experiment;(4)Using 120° and 90° conical indenters,a single abrasive particle plane scratch test was carried out,and the effects of wear sharpness on the surface morphology,scratch width,scratch bottom Ra value and cracks were analyzed and studied It was found that under the same scratch depth,with the wear of the indenter,the sharpness of the indenter wear increases,the chipping of the scratch edge becomes smaller,the ratio of the width of the scratch decreases,and the Ra value at the bottom of the scratch decreases.The influence of the conical indenter on the scratch morphology as the wear sharpness increases is greater than 90 ° conical indenter;(5)Using the 120° and 90° conical indenters,the plane scratch experiment of single abrasive particles was carried out,and the relationship between the wear sharpness and the amount of scratching process such as the scratching force,force ratio,and specific energy of scratching was analyzed.It is found that the scratching force,force ratio,etc.basically increase with the increase of the wear sharpness.While the scratch specific energy,the 120 ° conical indenter increases with the sharpness of wear,and its scratch specific energy decreases first and then increases;the specific energy of the 90 ° conical indenter gradually decreases as the wear progresses.This should be related to the "breaking" that occurs during the wear of the indenter.
Keywords/Search Tags:Diamond wear, Digital image processing, Characterization of the amount of wear, Single-abrasive particle scratch test, Scratch morphology, Scratch process
PDF Full Text Request
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