金刚石与磨料磨具工程

Struggle through the difficulty to embrace another glory——A brief analysis on economic situation of China superabrasives industry in 2016

LI Zhihong, SUN Zhaoda, ZHAO Bo, ZHAO Xinghao, WEN Shuying

2017, 37(5): 1-11. doi: 10.13394/j.cnki.jgszz.2017.5.0001

Abstract(274)

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Abstract:
The operation situation of superabrasives industry is briefly analyzed according to 11 tables and 19 figures, which cover some data of Chinese macro economy, the main indexes of the industry, the productions, imports and exports of superabrasive, and the annual reports of listed companies in 2016.It is found that indexes of the industry, such as total productivity, industrial added value, total profit and export data, all decrease continuously and yet they are worse than those of macro economy.These indicate that innovating and upgrading is of great emergence.However, some companies have developed new technologies and markets, which makes them realize exceptional increases, even more than 10%.They have laid a solid foundation for further development, as well as set good examples for the industry.Most enterprises have experienced a tough structural adjust, and now they are ready for another glory.

Effect of abrasive sizes on processing characteristics of fixed diamond aggregations pad lapping quartz glass

LING Shunzhi, MO Honglei, WANG Zhongxi, ZHU Yongwei

2017, 37(5): 12-18. doi: 10.13394/j.cnki.jgszz.2017.5.0002

Abstract(344)

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Abstract:
Lapping quartz glass is the former process of its ultra-smooth polishing process, which greatly affects its machining efficiency and final surface quality.To meet the hard and brittle characteristics of the quartz glass, a new fixed diamond aggregation pad (FDAP) was employed to study the high efficiency and low damage lapping process.The effect of original abrasive size, secondary abrasive size, applied load and slurry flow rate on the lapping performance was explored.After comprehensive optimization, the process parameters with high processing efficiency and excellent surface quality were obtained. The results show that the FDAP exhibits an excellent lapping performance.When the original abrasive size and secondary abrasive grain size are 1.0~2.0 μm and 20~25 μm respectively, with load 14 kPa and slurry flow rate 60 mL/min, the material removal rate of quartz glass reaches 2.64 μm/min and average surface roughness R_a is 54.2 nm.

Research on the relationship between acoustic emission signal and material removal rate during fixed abrasive lapping

TONG Haocheng, LI Jun, GUO Taiyu, MING Shun, ZHU Yongwei, ZUO Dunwen

2017, 37(5): 19-23. doi: 10.13394/j.cnki.jgszz.2017.5.0003

Abstract(352)

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Abstract:
Due to passivation and wear, fixed abrasive lapping pad needs to be conditioned.Material removal rate is one of the characteristic indexes to judge the condition of the lapping pad.The relationship between acoustic emission signal and material removal rate is beneficial to optimize conditioning of lapping pad, improve the processing efficiency and reduce the production cost.The effect of lapping pressure, lapping speed, abrasive size and slurry pH on the removal rate and acoustic emission signal is investigated in fixed abrasive lapping K9 glass.The linear regression equation of material removal rate and root mean square of acoustic emission signal is established.The results show that the influences of the four factors on material removal rate and acoustic emission signal is the same, and the prediction error of the regression equation is less than 5%.Acoustic emission technology can be used to predict material removal rate in lapping process, which lays the foundation for on-line monitoring fixed abrasive pad condition.

Analysis and experimental research of grinding wheel errors in cross grinding aspheric surfaces

CHEN Bing, HU Honglu, ZHONG Yixing, LI Shichun, DENG Chaohui, ZHAO Qingliang

2017, 37(5): 24-29,40. doi: 10.13394/j.cnki.jgszz.2017.5.0004

Abstract(311)

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Abstract:
To research the influences of grinding wheel errors on ultra-precision grinding aspheric surface quality in cross grinding, a variety of grinding wheel errors were analyzed theoretically, the influences of various grinding wheel errors on ultra-precision grinding aspheric surface quality were expounded, and some kind wheel errors were corrected and compensated to improve the surface quality.Finally, the aspheric surface grinding experiment was carried out to verify the correctness of grinding wheel errors compensation.The research provides technical reference for compensating wheel errors in ultra-precision grinding aspheric surfaces.

Design and debugging of the integrated system of the blade adaptive abrasive belt grinding unit

LIU Xiumei, XIAO Guijian, LIU Zhiwu, DING Qingchun, LIU Ying, LI Fei

2017, 37(5): 30-34. doi: 10.13394/j.cnki.jgszz.2017.5.0005

Abstract(269)

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Abstract:
In order to realize the system integration of aero engine blade self-adaption belt grinding unit, according to the production requirements determine the construction target and process of belt grinding unit system, establishing a system integration scheme for self-adaption belt grinding unit.Under the control of the grinding unit manufacturing execution support system, realizing the integration of grinding processing of a blade surface, edge and the blade root and the boss of the transition zone, the debugging proof the blade grinding unit could meet the design requirements surface and edge, blade root and other parts of the roughness and profile.

Preparing diamond tool at vacuum pressureless sintering with pre-alloy powder binder

HOU Ming, GUO Shenghui, GAO Jiyun, YANG Li, PENG Jinhui, WANG Liang, YE Xiaolei, LIANG Baoyan

2017, 37(5): 35-40. doi: 10.13394/j.cnki.jgszz.2017.5.0006

Abstract(362)

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Abstract:
Diamond tool binder samples were prepared using vacuum and pressureless sintering with Fe₄₀Cu₄₀Co₂₀ and Cu₈₀Sn₂₀ pre-alloy powder as raw material.The samples were compared with those sintered at the same process and elements but with mixed metal powder.The hardness, density and matrix morphology of matrices with pre-alloy powder and mixed metal powder were compared and analyzed using Rockwell hardness tester, Archimedes Drainage Act and SEM, respectively.Resultsshow that as temperature increases, the density and hardness of both matrices increase first and then decrease, with the maximum value at 860℃.The matrix sintered with pre-alloy powder at 860℃ performs a density increase of 5% and a hardness increase of HRB 7 MPa, compared with those of the matrix sintered with mixed metal powder.In conclusion, the pre-alloyed powder requires lower temperature and less time compared with the mixed metal powder to achieve the same performance.Therefore, it can avoid damages to the strength and quality of diamond.

Influence of wire speed on diamond wire saw and surface quality of silicon wafer

LI Hongda, QIN Juncun, XING Xu, MING Zhaokun

2017, 37(5): 41-44,49. doi: 10.13394/j.cnki.jgszz.2017.5.0007

Abstract(464)

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Abstract:
The wear of wire and the surface quality of silicon wafer under different wire speeds were studied.The micro and quantitative analysis of the used wire and silicon wafer was investigated by SEM and roughness instrument.The results showed that the smaller the wear of diamond wire with the wire speed increasing from 3.5 μm to 2.5 μm;;diamond wire cutting silicon materials for plastic and brittle mixed mode of removal of silicon surface profile showed a continuous groove, accompanied by a large number of scratches and pits, with the wire speed increasing the surface roughness of silicon wafer was gradually decreased, R_a、R_z and R_t decreased by 33.7%、37.8%、45.6%, the number of surface pits also gradually reduced.

Effect of high temperature performance of carbide on carbon fiber reinforced polymer(CFRP) cutting

YANG Xiaofan, LI Yousheng, LI Lingxiang, SHEN Zhihuang, LIU Judong

2017, 37(5): 45-49. doi: 10.13394/j.cnki.jgszz.2017.5.0008

Abstract(371)

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Abstract:
To study the effect of high temperature performance of carbide on CFRP cutting, two kinds of WC-Co based fine grain carbide materials with same main elements were prepared.The material A was added with trace TaC (NbC), and materials B did not add trace elements.High temperature hardnesses of two kinds of carbide materials were testing by high temperature Vickers hardness tester, and the CFRP was milling processed by the fine-cross-nick routers that were made of these two materials.The results showed that abrasive wear was the main reason of tool wear when the CFRP was milling processed by the fine-cross-nick router.The high temperature hardness of material A was higher than material B.Under the same using conditions, the wear resistance of material A was better than that of material B, the tool made of material A had a longer tool life, and more suitable for CFRP machining.

Research on grinding performance of CBN abrasive belt

XIAO Leyin, CHEN Jiarong, LIN Feng, XIE Zhigang, XIE Delong, CHEN Chao

2017, 37(5): 50-53. doi: 10.13394/j.cnki.jgszz.2017.5.0009

Abstract(274)

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CBN and corundum belts, at the same granularity, were used to grind 45 steel.Their grinding performance were analyzed and compared.Resultsshow that the grinding ratios of CBN belt and corundum belt are 210.4 and 18.9, respectively, which means that the wear resistance of CBN belt is better than that of corundum abrasive belt.It is also found that CBN belt does better than corundum belt in the surface quality of grinding workpiece, while the surface roughness R_a of the workpiece are almost the same, respectively 0.127 μm and 0.128 μm, and that the abrasive protrusion of CBN belt is higher, leading to superior initial grinding efficiency.In addition, the hardness of resin bond in corundum belt is small, which basically loses the grinding ability after grinding for 60 minutes, but nickel metal bond in CBN belt matches well with CBN abrasive, so that CBN belt could keep 28.2 g/h grinding efficiency after 180 minutes.

A kind of diamond wire saw for cutting reinforced concrete with low cost and high performance

ZHANG Zhiming, WANG Xianghui, MENG Yunkai

2017, 37(5): 54-57. doi: 10.13394/j.cnki.jgszz.2017.5.0010

Abstract(294)

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The effect of new superfine pre-alloyed powder and vulcanization of rubber on the cost and property of diamond wire saws were studied, which were used to cut reinforced concrete.A new diamond wire saw with low cost and high performance was developed and produced by using new superfine pre-alloyed powder, structure improvement of the diamond wire saw and optimization of the vulcanization process of rubber.The diamond wire saw was tested by cutting highly reinforced concrete crossbeam (the ratio of sectional area of steel bar to beam cross section >0.09) and the result of the test was analyzed.The result showed that the diamond wire saw used in the test has excellent sharpness and long lifetime with cutting speed achieved 2.0~2.8 m²/h and the lifetime achieved 2.7~3.3 m²/m, which was at the leading level of the industry.

Effects on the performance of small diameter diamond saws by pressureless sintering process

YANG Dong, CHEN Zhiqiang, WANG Xiaodong, WU Xiwang

2017, 37(5): 58-61. doi: 10.13394/j.cnki.jgszz.2017.5.0011

Abstract(365)

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Using sharpness and service life as indexes, the influences of sintering temperature, holding time, diamond concentration, diamond grit size on the performance of ф112 mm saws were investigated by single-factor experiment.The results show that the influence factors from large to little by turn are sintering temperature, diamond grit size, diamond concentration, holding time. The optimum conditions for the properties of ф112 mm saws are obtained as follows:sintering temperature 930℃, diamond grit size 35/40, diamond concentration 12%, holding time 60 min.

Research progress of PCBN without binder

KOU Zili, LIU Teng

2017, 37(5): 62-65,73. doi: 10.13394/j.cnki.jgszz.2017.5.0012

Abstract(315)

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Cubic boron nitride is widely used in modern manufacturing field, with its excellent characteristics.The performance requirements of cubic boron nitride are higher with the continuous improvement of manufacturing requirements, many countries in the world have developed the synthetic technology of pure phase of cubic boron nitride.In this paper, many efforts have been made to research preparation methods of polystalline cubic boron nitride (PCBN) without additive all over the world, and the various sintering methods of pure phase are also analyzed.Finally, the future development trend of PCBN without binder is prospected.

Thermal stability of cubic boron nitride of various types

WANG Yongkai, ZHANG Xiangfa, WEI Xing, ZHAO Haijun, LIANG Hao, LU Cuilian

2017, 37(5): 66-68. doi: 10.13394/j.cnki.jgszz.2017.5.0013

Abstract(327)

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To study the influence of CBN type on its thermal stability, different CBNs were studied using SEM and TG-DTA.Analysis on the thermal stability of CBN crystals of different colors or types were implemented to investigate the mechanism of CBN heat resistance.The results show that CBN thermal stability increases as its color goes dark;and that it increases with the increase of regularity and TI/TTI value.

Simulation of the effect of feeder on the cavity of sintered ceramic grinding wheel

ZHANG Jingqiang, WANG Qi, GUO Jianye, WANG Yunjiang

2017, 37(5): 69-73. doi: 10.13394/j.cnki.jgszz.2017.5.0014

Abstract(255)

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The mechanism of microwave sintering ceramic grinding wheel is complicated, and the feeder arrangement in the cavity had a great influence on the distribution of magnetic field.Therefore, HFSS, a high frequency electromagnetic simulation software, was used to establish models of microwave sintering furnace cavity, and the microwave electro-magnetic field distribution was simulated and analyzed with different numbers, sizes and positions of the feeder.The results show that the feeder inlet should be placed symmetrically with three centers, and that the size of the feeder should be 70 mm×50 mm×20 mm.In this condition, the electromagnetic field distribution in the furnace will be the best.

Research status of grain interface in polycrystalline diamond with different binders

HENG Jun, PIAN Xiaoxuan, SHI Chunyan, QIN Weili, LI Zhengxin, LI Xiaolong

2017, 37(5): 74-78,92. doi: 10.13394/j.cnki.jgszz.2017.5.0015

Abstract(383)

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There are many factors affecting the performance of PCD, the most important is the interface bonding of binder and diamond grain.The paper summarizes the performance of metal binder such as Co, Ni and nonmetal binder such as Si, B in the presence of internal state of polycrystalline diamond interface, the interface state and its principle, and finally draws the polycrystalline diamond with selection principle and development direction of binder.

Research and development of cubic boron nitride grinding wheel

SUN Huibing, ZHAO Yucheng, WANG Mingzhi, ZOU Qin, WAN Ming, WANG Weide, ZHANG Yafei, WANG Siyu, CHEN Hui

2017, 37(5): 79-85. doi: 10.13394/j.cnki.jgszz.2017.5.0016

Abstract(431)

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Abstract:
This paper presents the development and performance of CBN grinding wheels at home and abroad and the characteristics of metal (including electroplating and brazing), resin and vitrified bonded CBN grinding wheels respectively, describes the processing method of CBN abrasive grains, the organization control technology of pores in CBN grinding wheels.Moreover we discuss the existing gap of CBN grinding wheels between home and aboard in manufacturing, and propose that the CBN grinding wheels manufacture should be developed toward ultra-high speed, high efficiency and green manufacturing in future.

Test method of impact toughness index of superabrasives

BAO Hua, ZHANG Liang, FENG Bingqiang, MA Yafei, ZHANG Linzhou, ZHANG Fengling

2017, 37(5): 86-92. doi: 10.13394/j.cnki.jgszz.2017.5.0017

Abstract(468)

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Abstract:
The national standard, GB/T 33144-2016 Superabrasives-Test method of impact toughness index, has been approved and issued by General Administration of Quality Supervision, Inspection and Quarantine of the P.R.C and Standardization Administration of China in October 13, 2016.The date of this standard implementation is May 1, 2017.The standard specifies a test method of impact toughness index (TI) and thermal impact toughness index (TTI) of synthetic diamond for grit designation 20/25 to 325/400 and cubic boron nitride for grit designation 30/40 to 325/400.In this paper, we elaborate the technical contents of this standard in detail, so that the users can understand and carry out the standard better.

2017 Vol. 37, No. 5

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