金刚石与磨料磨具工程

Influence of plate wheel dressing on grain morphology of mono-layer brazed diamond grinding wheel

HU Hao, SU Honghua, DAI Jianbo

2016, 36(6): 1-5. doi: 10.13394/j.cnki.jgszz.2016.6.0001

Abstract(317)

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Abstract:
In order to reveal the influence of dressing plate wheel on grain morphology of mono-layer brazed diamond grinding wheel,the morphology was observed and measured in different phases of dressing by using the optical microscope. The changes of abrasive wear form,cutting edge width,top surface area and cutting edge radius were statistically analyzed to characterize the change of grain morphology. The results show that attritious wear mainly occurs in the process of dressing with plate wheel,and that a few grinding grains are fractured and sheared off. The ratio of wear mentioned above increases gradually. Meanwhile,with the increase of the dressing amount,the average cutting width and the average top surface area increase gradually,while the average cutting edge radius increases firstly and then decreases.

Machining characteristics of single crystal SiC wafer with copper lapping pad

LIANG Huazhuo, LU Jiabin, YAN Qiusheng

2016, 36(6): 6-10,14. doi: 10.13394/j.cnki.jgszz.2016.6.0002

Abstract(406)

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The Siface and C face of 6H-SiC single crystal wafer were lapped by using the copper based lapping pad with spiral grooves and the effects of lapping pressure,pad speed and abrasive size on the material removal rate and the surface roughness of SiC were studied. The results show that the lapping characteristics of C face and Siface have obvious difference. The C face is easier to lap and the material removal rate of C face is larger than that of the Siface. The lapping pressure is a key parameter that influences material removal rate and surface roughness. The higher the lapping pressure is,the larger the material removal rate is,but the surface roughness R_a increases as well. High lapping pressure can generate scratches on SiC surface. To achieve a better surface roughness,the lapping speed of the C face should be faster than that of the Siface. It's also found that agglomeration of the diamond abrasives will seriously affect the quality of the lapped surface. Therefore,the lapping quality of SiC surface with 3 μm diamond abrasive is better than that with 1 μm diamond abrasive. After lapping for 5 min with 3 μm diamond abrasive,the surface roughness of Siface decreases from original R_a 130 nm to R_a 5.20 nm,and the surface roughness of the C face decreases to R_a 5.49 nm.

Orthogonal experiment on coating material of resin bonded abrasive wire saw

BI Wenbo, GE Peiqi

2016, 36(6): 11-14. doi: 10.13394/j.cnki.jgszz.2016.6.0003

Abstract(339)

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Abstract:
In order to improve the production efficiency of epoxy-phenol bonded abrasive wire saw,imidazole,liquid polysulfide rubber and coupling agent were added into the coating material. The influence of components on wire saw performance was investigated with orthogonal experiment. The contents of phenol resin,liquid polysulfide rubber and coupling agent as well as the diamond concentration in the resin were chosen as the orthogonal experimental factors,while the evaluation indexes of the orthogonal experimental were the maximum cutting area of the wire saw and the gelatin time of the coating material.Resultsshow that imidazole content has the most significant influence on the indexes,followed by phenol resin content,diamond concentration,liquid polysulfide rubber and coupling agent,the best values of which are phenol resin 40.0 wt%,liquid polysulfide rubber 6.4 wt%,coupling agent 3.0 wt%,imidazole content 1.2 wt%,and diamond(concentration 450 mg/cm³) 49.4 wt%,respectively. When verified with the optimized formula,the maximum cutting area reaches 185.32 mm² and the gelatin time 130 s.

Optimization of HFCVD diamond coating deposition temperature compensating

JIAN Xiaogang, LEI Qiang, ZHANG Kuilin

2016, 36(6): 15-19,24. doi: 10.13394/j.cnki.jgszz.2016.6.0004

Abstract(442)

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Abstract:
In the process of the diamond coating deposition of hot filament chemical vapor deposition(HFCVD),the precise control of temperature distribution,especially the temperature of substrate is one of the main problems affect the quality of diamond film. The paper proposes a temperature compensating device to improve the temperature distribution based on HF-650. Arranging reflective plates on and surrounding the substrate improves the distribution of temperature by thermal reflection. Simulation by Fluent and test by improved device will be used to verify the improvement. It is shown that the compensating device can uniform the temperature distribution of HFCVD,reducing temperature fluctuate from 9.3% to 3.0%,which has been proved by practice. With the device,high quality diamond film that I_D/I_G=4.33 has been prepared,which is positive for diamond deposition.

Preparation of CVD microcrystalline diamond powders on Cu substrates

SHEN Xiaotian, SHEN Bin, WANG Xinchang, ZHAO Tianqi, SUN Fanghong

2016, 36(6): 20-24. doi: 10.13394/j.cnki.jgszz.2016.6.0005

Abstract(360)

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Ultrasonic grinding pretreatment is applied on Cu substrates to deposit microcrystalline diamonds with self-nucleation method by hot filament chemical vapor deposition(HFCVD). It is show that without ultrasonic grinding pretreatment,only a few microcrystalline diamonds can be deposited on the Cu substrate. When the duration of pretreatment is about 1 min,a large amount of microcrystalline diamonds is deposited on the substrates simultaneously. However,when the duration of pretreatment is more than 2 min,too many diamonds are deposited and there forms a diamond film on the substrate. The microcrystalline diamonds deposited by CVD methods exhibit a cubo-octahedral morphology and have the euhedral diamond faces with(111) and(100).

Polishing slurry of chemical mechanical polishing SUS304 ultrathin stainless steel sheet

QIN Hongquan, WANG Yongsheng, LI Qing, CHEN Jiapeng, LIU Zhenhui, SU Jianxiu

2016, 36(6): 25-28,34. doi: 10.13394/j.cnki.jgszz.2016.6.0006

Abstract(368)

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Flexible display has become a research hot spot as next generation display technology and stainless steel is one of the main materials of flexible large size display substrate. To realize a super-smooth no-damage surface on stainless steel,chemical mechanical polishing(CMP) is adopted. The influence of abrasive size and contents of dispersion agent,oxidant agent,abrasive and corrosion inhibitor agent on the material removal rate and the surface roughness of CMP 304 stainless steel had been studied by orthogonal tests. The results show that abrasive size has the most significant effect on the surface roughness,followed by contents of H₂O₂,glycerol,oxalic acid,abrasive in turn. The abrasive size has the maximum effect on the material removal rate,followed by contents of abrasive,glycerol,oxalic acid and H₂O₂.

Effect of hot-press sintering parameters on properties of super-abrasive wheel segments

YU Jianwu, WEN Cheng, HUANG Shuai, LONG Xiaobing, WU Yao

2016, 36(6): 29-34. doi: 10.13394/j.cnki.jgszz.2016.6.0007

Abstract(591)

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Abstract:
Metal-bonded diamond wheel has advantages on bonding strength and using life, which is traditionally sintered by high temperature,causing thermal damage to diamond abrasives and affecting the grinding performance and using life of diamond wheels. The temperature in hot-pressing sintering is lower than that in traditional high temperature sintering so that hot-pressing sintering effectively reduces thermal damage to diamond abrasives. Hot-pressing sintering method is used to fabricate metal-bonded diamond wheel segment using diamond grains with average size of 27 μm. Orthogonal tests with 3 factors and 3 levels are conducted,and effects of process parameters on mechanical properties of wheel segment are investigated. The results show that the best mechanical properties is obtained under temperature 650℃,pressure 25 MPa and holding temperature time 150 s; metallurgical adhesion between diamond and metal bond is also realized.

Simulation and experiment of the heat pipe grinding wheel with high frequency induction brazing

GAO Junjie, FU Yucan, CHEN Jiajia, GU Zhibin

2016, 36(6): 35-40. doi: 10.13394/j.cnki.jgszz.2016.6.0008

Abstract(327)

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An induction heater is designed to be suitable for high frequency induction heating heat-pipegrinding-wheel(HPGW). Through the simulation software, the influence of three parameters, namely magnitude of current,heating gap and coil angle,on the temperature distribution of the HPGW is analyzed.After the optimized parameter combination is optimized,the CBN HPGW is made by using the newly designed induction heater and high frequency induction brazing technology. The experiment results demonstrate that the substrate temperature distribution is both uniform and in agreement with the simulation. The solder combines the substrate and abrasives well while CBN abrasives distribute orderly. The design of brazing process parameters and heater structure is reasonable.

Grinding force of particle-reinforced titanium matrix in creep-feed deep grinding

SHEN Long, DING Wenfeng, LI Zheng, LIU Chaojie, WANG Xunyang

2016, 36(6): 41-46. doi: 10.13394/j.cnki.jgszz.2016.6.0009

Abstract(254)

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Grinding force is a significant indicator in grinding process,which has close relationship with machining effect. Creep-feed deep grinding experiments on particle-reinforced titanium matrix composites(PTMCs) were carried out with vitrified grinding wheels of different grain types to investigate the effect of grinding parameters and grain types on grinding force. The results show that grinding force of corundum wheels are 3 to 4 times larger than that of microcrystalline corundum wheel. Therefore,surface defect is easily produced on ground surface with corundum wheels. In conclusion,the microcrystalline corundum grinding wheel is more suitable for grinding of particle-reinforced titanium matrix composite in creep-feed deep grinding.

Influence of diamonds with different plating parameters on grinding performance of resin bond grinding wheel

FANG Lili, XUE Lisha

2016, 36(6): 47-50,56. doi: 10.13394/j.cnki.jgszz.2016.6.0010

Abstract(336)

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Different plated-diamonds made at different plating conditions were used as abrasives to fabricate resin grinding wheels to study the effect of plating technology and conditions on the performance of plateddiamond. The parallel, hardness and resistance of grinding wheels were detected as well. The results demonstrate that:the performance of grinding wheels is significantly improved when using plated diamond as abrasives,with the wear degree of grinding wheels remarkably reduced by 45.31%. When the electroplating process and weight-gaining rate are both similar,the abrasive resistance of grinding wheels that using grinding material made by vacuum evaporation of titanium coating process is better,demonstrated by the abrasion degree of grinding wheel cut down with 29.77%; the abrasive resistance of grinding wheels whose grinding material is plated-diamonds under high current and short time plating technology is better,the data illustrated a notable reduction by 29.43% in the abrasion degree of grinding wheels. The coating weight gain rate affects the growth status of Ni splinter coated on diamond surface,and the abrasive resistance of grinding wheels will decrease if the coating weight of plated diamond increases too fast.

Nano-metal oxides can be uniformly dispersed using isothermal hydrolyzing method

ZHANG Yan, ZANG Jianbing, XU Hanqing, HAN Chan, CHEN Libei, WANG Yanhui

2016, 36(6): 51-56. doi: 10.13394/j.cnki.jgszz.2016.6.0011

Abstract(331)

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To solve the problem that nano powders are easily to aggregate,isothermal hydrolyzing method is used to deposit nano ZrO₂ and nano TiO₂ onto carbon nano tubes(CNTs) and Si C at low temperature of 80 to 90℃. The products are characterized by using XRD,DSC and TEM.Resultsshow that all nano particles are uniformly and entirely deposited on the surface of isothermal hydrolyzed samples with no spare particles or aggregations. In conclusion,aggregation of nano particles could be effectively solved by using isothermal hydrolyzing method.

Residual stress of polycrystalline diamond compact

DAI Jiajia, CHEN Hui, GUO Dameng

2016, 36(6): 57-62. doi: 10.13394/j.cnki.jgszz.2016.6.0012

Abstract(360)

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Residual stress is widely spread in polycrystalline diamond compact(PDC) products,which leads to failure PDC. In this research,we studied the composition of residual stress and established an inspection method to analyze residual stress by using XRD. The distribution rule of the stress is also discussed. The influence of thickness of PCD layer,size of diamond particle,shape of interface and content of Co on PDC residual stress is studied to provide a reference for residual stress control. In conclusion,it is showed that:1) on the surface of diamond layer,the maximum appears in the centre and decreases along radial direction; 2) the stress near the interface between PCD layer and carbide matrix has significant influence on service character of PDC product.

Study on color change of synthetic type Ⅱa diamond crystals treated by electron irradiation

ZANG Chuanyi, YUAN Hengxin, LIU Bo, CHEN Xiaozhou, CHEN Kui, LI Ming

2016, 36(6): 63-65. doi: 10.13394/j.cnki.jgszz.2016.6.0013

Abstract(382)

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Type Ⅱa diamond crystals synthesized by using temperature gradient method were treated by electron irradiation through high energy electron accelerator. The samples were tested by colorimeter,Diamond View and FTIR. It is found that the initial colorless type Ⅱa diamond crystal changes into a pink color after the electron irradiation,and that there are some burning traces on the surface of the diamond. It is also shown that the color of fluorescence captured by Diamond View changes from light blue to golden.

Application of three-coordinate-measuring machine in superhard material products detection

GAO Yanbing, ZHANG Kexuan, BAO Hua, ZHAO Peng, LU: Shenfeng

2016, 36(6): 66-70. doi: 10.13394/j.cnki.jgszz.2016.6.0014

Abstract(319)

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The three-coordinate-measuring machine(CMM) is a high precision automated measuring equipment with wide range of detection. It is not only for conventional product dimensional tolerance and geometric tolerance test,and also in complex workpieces and complex dimension measure. In addition,it is applied in product of reverse development at the same time. CMM provides important technical data for us in daily product design and manufacturing process. This paper takes several measurement in practical work for examples to show that three coordinates measuring machine has played an important role in superhard products detection,and provides technical support for our scientific research,production and product development.

Development and test evaluation of PDC impact resistance testing device

ZHANG Tao, LU Canhua, BAO Yuhe, DOU Ming, LIU Juntao

2016, 36(6): 71-73,78. doi: 10.13394/j.cnki.jgszz.2016.6.0015

Abstract(371)

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According to the theory of percussion drilling fluctuation,the actual stress of polycrystalline diamond compact(PDC) working under the well was simulated. A new PDC impact resistant device is designed with new method. The impact resistance of PDC ZB1308,ZA1308,ZA1613 and ZA1913 was tested by using the device.It is shown that the minimum values are 30,60,80,85 J at the normal atmospheric temperature,and that the minimum values are 30,60,80,85 J at the high temperature. The result matches with the actual forces. The new device could effectively simulate the real stress of the PDC working under the well.

Research on new type of directional drilling PDC bit used in coal mine drill

WANG Chuanliu, JU Pei, GAO Xiaoliang

2016, 36(6): 74-78. doi: 10.13394/j.cnki.jgszz.2016.6.0016

Abstract(355)

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When drilling hard formation or staggered formation,normal single layer flat base bit wears heavily.Therefore,we developed a new kind of directional drilling polycrystalline diamond composite(PDC) bit and analyzed its rock breaking mechanism and stress property by using numerical simulation method.Resultsshow that rock breaking load of the new bit decreases by 36% and breaking efficiency increases by 50% compared with normal bits at the same working condition. Field tests were implemented with the new kind of bits. It turns out that when drilling hard formation or staggered formation,the life of new bits is 3 times as much as that of normal bits,and that the drilling efficiency almost doubles. New kind of PDC bit could decrease the drilling cost.

Performance of diamond saw blades on cutting superhard tile can be enhanced by bond weaken

LI Wei, SUN Meng, LI Hesheng

2016, 36(6): 79-82. doi: 10.13394/j.cnki.jgszz.2016.6.0017

Abstract(313)

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Superhard tile has high strength and hardness,while its abrasiveness is poor,which will burn common diamond blade easily. In order to solve this problem,a new bond-weaken tile blades is proposed by doping some graphite particle into metallic bond of tile blades. The function of graphite is to enhance the wear of bond and reduce the friction between blade and tile,thus ensuring all the diamond exposed for cutting in time to guarantee the cutting speed and stability. It is proved that bond-weaken blades performs higher cutting speed with graphite,and that when adding 6%(mass fraction) graphite,the cutting speed on superhard tile is enhanced by more than 20% actually.

Characterization of polycrystalline diamond compact with non-planar surfaces for drilling hard-formation

ZHAO Dongpeng, MA Shanshan, NIU Tongjian, LI Sicheng, ZHANG Chunlin, FANG Haijiang

2016, 36(6): 83-86. doi: 10.13394/j.cnki.jgszz.2016.6.0018

Abstract(315)

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Utilizing domestic hinge-type cubic press,the non-planar face polycrystalline diamond compact(namely,the ridge cutter) was synthesized under high temperature and high pressure(HPHT) processes. The laboratory testing results show that compared with the planar cutter,the ridge cutter performs wear resistance increase of 40%,impact resistance increase of 30.8%,and cutting force reduce of 36.8%. Meanwhile,ridge cutter with the optimal caster angle could improve the drilling footage and drilling rate. The drilling data indicate that the compared with the planar cutter,the drilling footage and drilling rate of ridge cutter are increased by 78.1% and 38.9%,respectively.

2016 Vol. 36, No. 6

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