Research on a New Type of Diamond Saw Plate

With the developing of stone material, diamond saw pl ate is used widely, and in order to increase cutting efficiency and life-span o f diamond saw plate, there are a lot of research jobs of segment for diamond saw plate. Layered segment for diamond saw plate is to divide single segment into s everal cutting tools by its structure, then increases rock-cutting faces. For i mpregnated man-made diamond saw plate, the bonding strength of diamonds with ma trix material has great effect on its life and service. Diamond is a kind of non metal and there is such high interface energy between diamond and common metals or alloys that diamond surface can’t be soaked by low melt-point metal or allo y. Diamonds are hold in metal matrix of working layer only mechanically, rather than bonded chemically, so the usage rate of diamonds in working layer is very l ow. Weakly impregnated method refers to covering diamonds with a thin layer of tu ngsten carbide mechanically by physical method, and chemical plating membrane re fers to coating a layer of carbide, which can react with the carbon atoms on the surface of diamond by chemical method and be soaked by matrix metal. In this pa per it analyses working mechanism and sintering process of layered segment of di amond saw plate by means of resistor hot-pressing sintering, it points out shor tages of layered structure, and raises using weakly impregnated layer instead of pure matrix layer, then overcomes the pure matrix layer slipping by pulling out diamonds earlier to improve cutting efficiency of saw plate, in the same time u ses diamond grains of chemical plating membrane proposed then preventing the hea t-hurting to diamond grains in working layer during the process of welding and sintering and improving the bonding strength of diamond with matrix, then improv ing life-span and aging of diamond saw. The theory of the design of mixed holding of diamonds by matrix of saw plate assures that chemical plating diamonds in working layer cut rock and weakly impr egnated diamonds in weakly impregnated layer make segment expose, then design a new type of layered segment for diamond saw plate.

Finite Element Analysis of Diamond Saw Blades to Prevent Steel Base Wear

The FEM analysis of stress and deformation of steel base of the special diamond saw blades are carried out.The small carbide round segments are welded on the side of blades in order to increase the side wear re sistance of blade.Comparing with conventional saw blade,the maximum stress val ues of reasonable special saw blade are reduced respectively about 17%20% 33%,and the maximum deformation values are reduced respectively about 26%22 %44.7%in thetangential(X),radial(Y)and axial(Z)direction.The stress conce ntration zone is decreased for the special structure diamond saw blade.The stru ctures of diamond saw blade with different number of hard material pellet are an alyzed and optimized.

Quantitative Analysis of the Loads Acting on the Abrasive Grits in the Diamond Sawing of Granites

An experimental study was carried out to quantitati ve ly evaluate the loads acting on the diamond grits during circular sawing of two kinds of typical granite with diamond segmented saw blade. Measurements were mad e of the horizontal and vertical force components and the consumed power in order to obtain the tangential and the normal force components. The temperatures at the diamond-granite contact zone were measured using a foil thermocouple. T he measurement, together with the net sawing power, was subsequently used to est imate the energy partition to the granite by a temperature matching technique. B ased on the energy partition values, the temperatures at individual cutting poin ts were estimated using an analytical model. SEM was used to follow the topograp hies of worn diamond segments. The average force acting on each diamond grit was found to be only 4% of the diamond compressive strength measured by a static me thod. The strength disparity of diamond grits and the random protrusion of grits beyond bond matrix should be significant factors in accounting for the wear of diamond grits. The wear of diamond grits was also found to be closely related to the high temperatures generated at individual cutting points and the pop-outs of diamonds from the bond matrix might be mainly attributed to the heat conducte d to the segments.

Influences of magnetic treatment on microstructure densification of diamond saw segments

The heated test pieces were treated with alternating magnetic field by self-made experimental facility firstly. And influences of magnetic treatment on microstructure densification of Diamond Saw Segments were studied through hardness testing, ultrasonic testing, metallurgical structure and fracture pattern analysis by comparative method. The mechanism of magnetic treatment is analyzed and discussed in the end. The results show that the hardness of test pieces after magnetized are harder than before, that HRB hardness is improved by 3.58 on average. The sound path and amplitude of echo wave both decrease in test pieces after magnetized. The relative pad value of echo wave is regularly related with the microstructure densification, what is profound to further establish the regularity studying the degree of matrices densification using ultrasonic testing. The pores become few and pore shape gradually spheroidizing with the magnetic treatment, and matrices are more homogeneous and compact than the without by metallographic microscope. The degree of matrices densification is further improved after magnetized. The average crystal grain size is finer than the without, and the reason of grain refining is that densification of diamond saw blade improved. Magnetic treatment can act as one kind of effective technique to improve the microstructure densification of diamond saw segments.

Research on Cutting Force of Ultrasonic Diamond Wire Saw

Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.

Sawing Performance Comparison of Brazed and Sintered Diamond Wires

Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances of brazed diamond wire have been reported, seldom do these studies refer to its process characteristics. Sawing performances of a brazed diamond wire are investigated and compared with those of a sintered diamond wire on a wire saw machine. The surface topographies of beads selected from the two wires are micro observed before sawing. The sawing tests are carried out in constant feed rate feeding（CFF） and constant normal force feeding（CNFF）. In CFF test, sawing force, power, and the cut depths of positions on contact curve are measured. Then, coupled with the observations of beads topographies, sawing force and its ratio, relations of power against material removal rate, and contact curve linearity are compared and discussed. In CNFF test, the sawing rates of the two wires are investigated. The results indicate that the brazed wire performs with lower sawing force（less 16% of tangential force and 28% of normal force）, more energy efficiency（nearly one-fifth of sawing power is saved）, at a higher sawing rate （the rate is doubled） and with better contact curve linearity as compared with the sintered wire. This proposed research experimentally evaluates the sawing performances of brazed diamond wire from the aspect of process parameters, which can provide a basis for popularizing the brazed diamond wire.

Study on swarf when sawing granite with diamond wire

The diamond wire-sawing process was developed to cut granite in both quarries and block processing plants.In this paper,swarf was collected from different areas along the sawing arc when sawing three granites.The particle size distribution and the morphology of the swarf were investigated systematically,along with the swarf formation mechanism in sawing.Granite swarf formation was dominated by transgranular fractures based on the morphology of sawn granite chips and the analysis of sawn chip size.A long cutting arc increased the movement among the swarf,tool,and workpiece,thereby inducing a secondary fracture in the sawn chip.

Polycrystalline diamond mini-cubes for sawing applications

Diamond grits are indispensable for sawing granite or concrete.Each year about 1 000 tons of diamond grits are consumed for such purposes.In all cases,mono crystalline diamond is used.However, polycrystalline grits(polygrits) are generally better performed than mono grits as abrasives.For example,poly grits of cubic boron nitride(e.g.Borazon(?) CBN-550 of Diamond Innovations) can cut faster and they last longer than mono grits(e.g.Borazon(?) CBN-500). Polygrits of alumina(e.g.Cubitron(?) of 3M) also out perform by far glassy grits(e.g.white alumina).For diamond superabrasives,micron polygrits formed by shock waves may polish as fast as mono grits of the same size,but without causing as much scratches due to the presence of smaller sintered grains.The improved performance of poly grits is attributed to their ability to micro chipping that renews the sharp cutting corners from time to time.By contrast,mono grits tend to round off at low cutting force or macro fracture at high cutting force,so they may lose the cutting ability rapidly. For sawing granite with mesh sizes 40/50 or coarser,poly grits of diamond have not been available until recently.In this research,we have made polygrits in mini cube with sizes of 18/20,20/25,and 30/40.Turbo grinders and wire saws were made by brazing both mono grits and polygrits on steel substrates.Cutting performance on granite demonstrated that grinding speed was faster with turbo grinder,and the surface finish was smoother with wire saw for poly grits than mono ones. Polygrits and mono grits of diamond were mixed for comparison(upper left).Polygrits of mini cubes were brazed on the pearl of a wire saw(upper right).Mono diamond grits were brazed on a turbo grinder(bottom diagrams ).

THE WEAR MODES AND MECHANISMS OFDIAMONDS IN SAWING HARD STONE

Four wear modes and four wear mechanisms of diamonds in sawblades are identified in a study of varied segments damaged in field operation of sawing hard stone. The four wear mechanisms are impactshearing, fatiguing, pullingout and thermal effects. Surface erosion is the result of thermal effects, while impactshearing and fatiguing lead to macro and microfracture, and pullingout results in wholesale dislodgement of diamonds provided the inequality Fn>M/(μλδ) is satisfied.

Experimental Study on the Machining Technology of ZrO_2 Ceramics Using Diamond Wire Saw with Ultrasonic Vibration

The influence of different technological parameter on material remove rate and surface quality of ZrO2 ceramics is studied using the cutting machining method of electroplate diamond wire saw with ultrasonic vibration.Experimental results show that,compared with the same experiment condition without ultrasonic vibration,this cutting method has the advantages of high material remove rate,good surface quality,little brokenness and so on.

Historical developments and future prospects of saw diamond

More than 1 000 tons of saw diamond grits were consumed worldwide in 2007.Even with such a mature industry,there are still major improvements possible in developing new grits.The DiaCanTM technology with patterned diamond seeding can boost the production yield of coarse mesh diamonds（e.g. 30/40）.Moreover,the DiaMind crystals formed contain a visible core.This diamond-in-diamond architecture allows self-sharpening during sawing application.Furthermore,a revolutionary polycrystalline diamond superabrasive with cubical shape was fabricated to further increase the sawing efficiency and tool longevity.Such DiaCubeTM polygrits were made tools by brazing them on pearls of wire saws and on the surface of turbo grinders. The pros and cons of major designs of high-pressure equipment for diamond synthesis were discussed with the recommendation to combine the merits of belt apparatus and cubic press.This tooling synergism may increase diamond yield at reduced cost for massive production of saw grits. In 1997 Sung Chien-Min filed a series US patents that described the art of making patterned diamond tools with diamond grits forming an array in three dimensions.He also made the debut of the world’ s first brazing tools with patterned diamond distribution at the stone exhibition in Verona in 1998（also in Nuremberg in 1999）.The patterned diamond saws were introduced by Korean companies in 2005 with the demonstration of increased cutting speeds and prolonged tool lives.

Research on Cutting Trajectory of Electroplated Diamond Wire Saw

The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite element method. It shows that the cutting stress is uniformly distributed along the direction of the workpiece width in the steady state. A mathematical equation of sawing trajectory was established by using the superposition principle and the cutting experiment of wire saw to calculate the cutting trajectory. The comparison of the theoretical trajectory with the calculated one indicates that the error is less than 15%. The research results provide a theoretic basis for optimization of the saw's cutting process parameters.

SAW filter with AIN on diamond

Diamond surface acoustic wave(SAW) has been used to boost the frequency of thin film filters made of piezoelectric materials.Many designs have been tested and with significant results,in particular,AlN on diamond(AlNoD) as the interface for transmitting Rayleigh wave was studied extensively .However,in all cases,nano crystalline or microcrystalline AlN coatings were deposited,typically by sputtering or CVD,on polycrystalline diamond film.The diamond film itself may contain nano or micro grains that are deposited by CVD.The presence of extensive grain boundaries in AlN can attenuate rapidly the propagation of Rayleigh wave.Moreover,the bonding between loose atomic packing of AlN and tight lattice of diamond is weak so much of the mechanical energy is dissipated as heat.In fact,the energy loss is much higher than energy transmitted during the resonating process.In this research,we attempted to improve the matching of atoms at the interface of AlNoD by doping AlN lattice with boron atoms.The shrinking of the lattice may allow more atoms are aligned at the interface.Moreover,a method of coupling single crystal AlN on single crystal diamond is proposed.Such a coupling can maximize the signal-to-noise ratio of the resonating AlNoD at the same time minimize the insertion loss of the SAW filter.

金刚石SAW滤波器的设计和制作

通信系统向高频的发展趋势使声表面波(SAW)滤波器技术面临着越来越多的挑战。利用传统材料制作SAW滤波器的中心频率很难达到GHz频段,因此探索在高声速材料基础上制作SAW滤波器成为一种必然趋势。基于高声速材料金刚石设计了IDT/ZnO/金刚石结构的薄膜SAW滤波器,设计了镜像阻抗连接IDT的结构参数,并采用ADS软件对该结构进行了建模仿真。然后,通过ZnO薄膜制备工艺和IDT电极制备工艺,获得了金刚石SAW滤波器样品。最后,采用RF探针台对所制得的样品进行了性能测试和数据分析。测试结果表明,在金刚石厚膜衬底上获得了频率超过1 GHz的SAW滤波器样品。

金刚石线切割单晶硅制绒研究进展

对常用的几种单晶硅片制绒技术,如添加剂辅助碱液刻蚀制绒工艺、酸液刻蚀制绒工艺、金属离子催化的化学制绒以及表面预处理(热处理、机械抛光和电化学预处理)叠加碱液刻蚀制绒工艺等进行了介绍。并对不同工艺的制绒原理、技术特点和应用情况等进行了对比分析,认为添加剂辅助碱液刻蚀制绒工艺应用较多;热处理叠加碱液刻蚀制绒工艺相较于其他制绒工艺,可减少溶液消耗、硅料消耗和简化工艺处理步骤等,可实现降低晶体硅太阳电池制造成本及硅片薄片化的目的。

ZnO/IDT/金刚石结构SAW滤波器的设计和制作

传统材料制备的声表面波(SAW)滤波器的中心频率f大多位于较低的频段(f<500 MHz),但是无线通信频段逐渐向着高频化的方向发展,因此在SAW器件领域中引入高声速材料如金刚石以提高中心频率成为一种必然趋势。基于金刚石材料、采用ZnO/IDT/金刚石新型结构,设计了交错叉指结构和镜像阻抗连接结构的叉指换能器(IDT)参数。通过优化的工艺制备流程,获得了金刚石SAW滤波器样品。最后采用RF探针台对样品进行了性能测试和数据分析。测试结果表明制备的SAW滤波器样品的测试结果与理论值比较符合,交错叉指结构滤波器获得了很低的插损,镜像阻抗连接结构滤波器有效地提高了带外抑制度。样品IDT指宽2μm,SAW滤波器中心频率可达0.775 GHz。

SAW器件用金刚石膜的制备工艺研究

针对声表面波(SAW)器件对金刚石膜的要求,采用石英钟罩式微波等离子体化学气相沉积(MPCVD)装置,研究了不同气体体系对金刚石膜生长速率、电阻率、表面形貌、表层C化合态及相对含量(粒子数分数XC)的影响。结果表明:在H2-CH3COCH3、CH4-H2-Ar和CH4-H2-N2三种气体体系下,金刚石膜的生长速率分别达0.63,0.59和0.58μm/h,较常规CH4-H2体系提高了1倍左右,且金刚石膜电阻率高(1010Ω.cm)、晶型好、晶粒尺寸小、表层金刚石C—C键相对含量高(XC>80%)。氧、氩和氮对提高金刚石膜的生长速率和质量效果显著。

基于金刚石绳锯切割技术在老旧桥梁拆除工程中应用的研究

随着城市化进程的加快和交通需求的日益增长,老旧桥梁的拆除与重建成为提升道路通行能力和安全性的重要举措。金刚石绳锯切割技术因其施工快速、便捷、经济、环保且无需爆破等特点,在老旧桥梁拆除工程中得到了广泛应用。本文基于石家庄市北三环老旧桥梁拆除及重建项目,重点探讨了金刚石绳锯切割技术在该领域的应用及其优势,通过案例分析展示了其施工流程、技术要点及安全控制措施,为类似工程提供了参考。

Remarkable achievements,splendid future——Celebrating the 45^(th) anniversary of synthetic diamond of China

The development of China as the world’s manufacturing house is best exemplified in the industry of diamond superabrasives.Diamond is indispensable in the creation of industrial infrastructure,including the construction of roads and building of houses.The world’s diamond was provided mainly by countries outside China in last century.However,a"great leap forward"has taken shape with rapid expansion in Chinese diamond-making capabilities from the enlargement of the equipment(cubic presses) and improvements in diamond yield and product quality in the end of last century.At the turn of this century,China outpaced the rest world combined in the total diamond output,became the largest producer in the world indubitably.In 2007,China produced nearly 4.4 billion carats,80%of the world’s diamond total output.The Chinese diamond well accepted in the world can be seen in the export statistics of China & import statistics of developed countries in this paper.For example,59%of USA imported diamonds were from China in 2007;in Japan, 40%. This report contains a survey of some main industrial sectors that use diamond superabrasives.Overall,22 tables and figures are used to portray the many facets of superabrasives,including cubic boron nitride.The report also discusses several challenges facing Chinese diamonds,such as the vast price difference between imported diamond grit produced outside China and domestic supply.This paper also presents an outlook of the future development of the Chinese superabrasives industry basing on the Chinese macroeconomics and the recent data of the end-users as well as their future development trend.The paper concludes by proposing that although remarkable achievements have been made in the past 45 years,given the fact that Chinese superabrasives industry still lags behind that from the advanced countries on a multitude of variables,further endeavor should be made to make China a super country in the superabrasives industry in the world.

基于ABAQUS的金刚石锯片切割工件破碎过程数值模拟研究

通过数值模拟的手段优化金刚石的排布方式,建立了C25混凝土材料的本构模型和金刚石锯片与C25混凝土的交互作用模型,通过该模型能够预测混凝土破碎过程,计算出切割过程中刀头和混凝土的应力和应变分布。建立了三种不同金刚石排布的锯片与C25混凝土的切割模型,计算了不同金刚石排布方式下切割材料和刀头的应力、应变分布。通过该模型可以改变金刚石排布、胎体材料属性以及切割材料属性来计算出不同边界条件下的金刚石、胎体以及切割材料的应力、应变和位移等结果,为金刚石锯片的结构设计和胎体材料设计提供理论指导。通过模拟切割计算,可以节省大量的切割材料,降低设计成本。从三种不同金刚石排布的锯片切割C25混凝土计算出的应力和应变结果得出,金刚石排布方案一的金刚石破碎混凝土的效率最高,切割速度最快。