Font Size: a A A

Grinding Of Cemented Carbide And Discrete Element Method Simulation Experiment Under Two-dimensional Compressive Stress

Posted on:2015-06-27Degree:MasterType:Thesis
Country:ChinaCandidate:X ZhangFull Text:PDF
GTID:2181330431487503Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
For its excellent mechanical properties, cemented carbide has been widelyapplied in the actual production and machining. As the improvement andenhancement of carbide processing technology, people have a higher requirement onprocessing quality of the cemented carbide product. Because of the hard brittle of thecemented carbide, it will resulted in damage and crack in the process of grinding, andshortening the life of it, hindering its development. Therefore, avoiding and reducingmaterial damage in the processing of cemented carbide and mastering the materialremoval mechanism is a key for machining carbide, it is also the important researchtopic of carbide processing and applications. This thesis combining the discreteelement method simulation and experimental study of cemented carbide, thecemented carbide YG10X was processed under2D compressive stress and its surfacemorphology was studied, and its structural characteristics and damage situation wereanalyzed by changing processing parameters, the influence of processing parameterson of hard alloy material, damage and affect the in-depth analysis, these works hasimportant scientific significance and engineering application background fordeveloping the processing technology of high efficiency and low damage forcemented carbide.The whole thesis was divided into six chapters, and the content of each chapterwas briefly described as follows.In chapter one, an introduction of the background of Cemented carbide wasgiven, its research achievements was reviewed, and the processing mechanism ofcemented carbide are analyzed. According to the application of the discrete elementmethod and research situation in this field at home and abroad, the main researchcontents and the significance of this thesis were outlined.In chapter two, the loading device of cemented carbide scratch test undertwo-dimensional compressive stress was designed, and the scratch test study wascarried out, the scratch force and crack extension rule of the cemented carbide weregot, the crack propagation in the surface/subsurface was observed, and the influenceof the pre-stress on cemented carbide was analyzed qualitatively.In chapter three, the grinding experiment of cemented carbide was carried undertwo-dimensional compressive stress by using orthogonal experiment method. The Kistler dynamometer was used to measure the change of grinding force underdifferent stress, combining with surface damage and the effect of surface roughness ofcemented carbide grinding surface under different processing parameters, theinfluence of the pre-stress on grinding crack propagation rule and the processingquality of cemented carbide was revealed.In chapter four, according to the basic principle of Indentation fracturemechanics model of hard and brittle material, the crack formation mechanism ofcemented carbide was discussed, the damage situation of the material and the reasonof crack produced were analyzed. By observing the Cross section under differentpre-stress, the effective methods to suppress crack expansion of cemented carbide inthe machining process.In chapter five, the Cluster method in the software PFC3Dwas used, the discreteelement model of cemented carbide scratch test was set up. The micro-parameters ofDEM model were calibration by some tests, and the discrete element simulation ofscratch test under the pre-stress, the propagation situation of crack in the scratchprocess was got.Finally, the whole work of this thesis was summarized systematically, and theoutlook for further study was discussed.
Keywords/Search Tags:Cemented carbide, Pre-stress, Grinding, Discrete Element Method, Crack
PDF Full Text Request
Related items