Study On Effect Of Magnetic Susceptibility On The Properties Of Micropowder Of Synthetic Diamond

With the development of industrial mass and lower cost production technology,synthesis diamond micropowder with excellent properties have been applied much widely in cutting,grinding,polish of rigid hard materials.It has been researching for some years that what and how factors effect the mechanical properties of micropowder diamond,and how to chracterize it.In order to figure out the factors and reason of effecting on micropowder diamond,the experiment is conducted by the means of magnetisation measuring and glass cutting with making diamond cuting wire.This thesis studies five different types of domestic produced synthetic diamond single crystal.In the meantime,the properties of corresponding synthetic diamond powder are analyzed and the electroplated wire saw is manufactured to measure the application characters of the powder.Magnetic susceptibility detection of synthetic diamond single crystal and powder are carried out using the JCC-B detector.Other properties include compressive strength,TI,TTI,morphology,ash component and heat stability are carefully measured.These measurements are conduct with a series of equipment,which include the ZMC-II superhard abrasive compressive strength tester,TI-03 B synthetic diamond shock strength tester,stereomicroscope,scanning electron microscope,EDS energy spectrum analyzer and micro differential thermal scale.Cutting experiment is carried out for the synthetic diamond fine wire saw to measure the cutting properties under various magnetic susceptibility.Experimental data is then analyzed from regression.Experiment results are as below.1.Different manufacturing process would significantly influence the morphology,content of wrapped internals and magnetic susceptibility of synthetic diamond.The JR1 and JR2 single crystal produced by flake catalyst contain more impurities,have inferior crystal form and with higher magnetic susceptibility.On the other hand,the functional T,HWD40 and HWD92 produced by powder catalyst have more complete crystal form,relatively lower level of impurities and magnetic susceptibility.It has been found that the broken micro powder of diamond is directly associated with the raw material.HHM-C,HHM-B and micro powder crystal are most likely flaked and long striped,and with high magnetic susceptibility.On the contrary,HHM-P,HWD40 and HWD92 has blocked or spherical type of crystal form and with low magnetic susceptibility.2.Magnetic susceptibility has significant influence over the properties of diamond single crystal: The higher the magnetic susceptibility is,the lower the single particle compressive strength,T1 and TT1 are,which depict negative correlations.Among these relations,magnetic susceptibility is most influential to the single particle compressive strength.3.The ash crystallization characters of different types of synthetic crystal single crystal have the same trend as it of the corresponding micro powder broken material.The higher the magnetic susceptibility is,the higher the ash component ratio of synthetic single crystal and micro powder,which shows a positive correlation.4.The heat stability of synthetic diamond micro broken material decreases as the magnetic susceptibility grows,which is negative correlated.In the experiments,specimen 1# with highest magnetic susceptibility has the worst heat stability,which starts to lose weight at 660?.The extrapolated starting temperature is 583? and the ratio of weight lost is 66.21%.Specimen 5# has the best heat stability,which starts to lose weight slowly at 660? and the 775? as the extrapolated starting temperature.The ratio of weight lost is 39.33%.This indicates that specimen 1# is more etching than 5# under high temperature.5.The application properties of synthetic diamond micro powder deteriorates as the magnetic susceptibility increases.The abrasive with high magnetic susceptibility appears to have severe “nickel tumor”,which leads to non-uniform distribution of abrasive and bad cutting characters.Therefore,the magnetic susceptibility could serve as an important criteria to judgement the functionalities of synthetic diamond,micro powder and the electroplated wire saws.Additionally,magnetic susceptibility could also be the key reference during the manufacturing processes of these products.