Profiled rotary dresser with controlled size and distribution of abrasive grits: Performance assessment

This paper reports on a novel proprietary profiled rotary dresser which, in contrast with conventional tools, enables a controlled arrangement of geometrically defined abrasives over complex profiles. Output forces and abrasives’ wear were investigated during dressing and grinding tests. This showed a significant reduction in radial dressing forces (˜37%) and volumetric loss of material per grit (˜21%) when compared with conventional tools, together with low grinding forces and workpiece surface roughness variability for different wear conditions. The novel dresser proves the ability to obtain uniform wear rates along complex profiles, while allowing abrasive segment replacement to restore the dressing conditions.     

Specific Energy Prediction for Circular Diamond Saw in Cutting Different Types of Rocks Using Multivariable Linear Regression Analysis

Circular diamond saw performance is affected by a variety of factors. The principal factors requiring consideration when predicting cutting rates are the type and operating features of a diamond saw and the rock characteristics. The laboratory experimental tests are carried out on three groups of rocks (16 types) cut with the help of three types of diamond disk saws with different feed rates and cutting depths at constant peripheral velocity. The quantitative determinations of a wide range of textural, mechanical, and intact properties of rocks are also made. The relationship between the specific cutting energy SE _cut of the sawblade operating parameters and rock properties is established. Applying multivariable linear regression analysis, the predictive model of SE _cut is developed based on the rock property data. Models verified by statistical tests prove their practical validity. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 56–80, May–June, 2005.     

Research on maximizing the diamond content of diamond/SiC composite

Diamond content is a key factor affecting diamond/SiC composite performance, especially thermal and mechanical properties, but the composite with high diamond content manufacturing is still challenging issues. Hot mold pressing combined with liquid silicon infiltration to make diamond/SiC composites with high diamond content and relative density has been proposed in this paper. In addition, the effect of diamond particle size on the maximization of diamond content as well as properties of the composites were evaluated. The experiment shows that the content of diamond in the composites increases with the increase of the diamond particle size. When the particle size of diamond is 400 µm, the volume fraction of diamond reaches 59.08%. The highest thermal conductivity (d_dia= 300 µm) and highest bending strength (d_dia= 50 µm) are 616.77 W/m K (It is the maximum TC of diamond/SiC prepared by pressureless infiltration at present) and 380 MPa, respectively. This work provides a novel and efficient preparation method for further improving the thermal conductivity of diamond/SiC composites.     

Microstructure and properties of diamond/SiC composites prepared by tape-casting and chemical vapor infiltration process

This article reported a novel method for preparing diamond/SiC composites by tape-casting and chemical vapor infiltration (CVI) process, and the advantages of this method were discussed. The diamond particle was proved to be thermally stable under CVI conditions and the CVI diamond/SiC composites only contained diamond and CVI-SiC phases. The SEM and TEM results showed a strong interfacial bonding existed between diamond and CVI-SiC matrix. Due to the strong bonding, the surface HRA hardness could reach up to 98.4 (HV 50 ± 5 GPa) and the thermal conductivity (TC) of composites was five times higher than that of pure CVI-SiC matrix. Additionally, the effects of diamond particle size on microstructure and properties of composites were also investigated. With the increasing of particle size, the density and TC of composites with the size 27 μm reached 2.940 g/cm³ and 82 W/(m K), respectively.     

Effects of scratching directions on AFM-based abrasive abrasion process

AFM-based single abrasive abrasion process is widely employed in the surface micro/nanomachining for fabrication of structures at the nanometer scale. The wear depth and roughness are significantly important in the application of these structures. To study effects of scratching directions on the wear depth and roughness within the wear mark, single groove scratching test and wear test on the surface of polished single crystal silicon were carried out using AFM with a pyramidal diamond tip. Single groove scratching tests indicated that tip geometry leads to different removal states such as cutting and plowing. At the same load, deeper wear depth and rougher surface were produced by using the scratching direction perpendicular to the long axis of the cantilever rather than parallel to the long axis of the cantilever. Surface roughness decreases with respect to the feed scratching perpendicular to the long axis of the cantilever, whereas while scratching along the long axis of the cantilever, the surface roughness is rougher at the small feed. This is attributed to the different stiffness of the cantilever along different scratching directions and different removal states between the tip and sample.     

金刚石框架锯锯切研究（2）一锯切破碎机理

在对金刚石框架锯锯切加工动力学研究的基础上，通过单颗粒划痕和单个金刚石结块切削大理石试验，模拟金刚石框架锯锯切过程中，金刚石颗粒和结块在不同加工条件下的切削过程；测量分析了切削力、表面沟槽轮廊和有效切削磨粒数；观察并分析了加工表面形貌；运用岩石脆性断裂力学理论，分析了单颗粒金刚石切削机理。通过金刚石框架锯发加工大理石的切屑粒度分布分析，指出了实际加工切削条件对锯切破碎机理的影响。研究结果证实了金刚石框架锯锯工加工动力学研究的一些基本结论，最后提出了金刚石框架锯锯切大理石破碎机理模型。     

金刚石薄膜的抛光技术

介绍了目前正在研究和应用的金刚石薄膜抛光技术，并对它们的原理、特点和适用范围进行了分析和总结。     

金刚石薄膜的制备及应用

综合叙述了金刚石薄膜的制备方法,并比较了他们的优缺点,金刚石薄膜的形成和生长情况及在各个领域的应用前景     

基于Diamond机械手的大批量、多类型分选装备研究

本文密切结合某电池生产企业的生产需求,研究用Diamond机械手搭建锂离子电池分选装备的布局问题.在分析可充电电池分选工艺流程的基础上,提出以Diamond机械手为硬件核心,结合企业原有装备,搭建可充电电池自动分选系统的总体方案.该方案具有制造成本低、分选批量大、分选类型多等特点.采用SOLIDWORKS软件建立了该混联装备的三维实体模型,运用MATLAB软件实现了分选仿真.     

基于气中放电辅助修整金刚石砂轮的试验研究

提出了一种新型的基于气中放电辅助金刚石砂轮在线修整法,它把气中火花放电修整法和金刚石笔机械修整法有机结合在一起,能实现光学曲线磨床上金刚石砂轮的高效、高精度、低成本和不得使用任何冷却液的在线修整。采用自制的试验装置在MK9025数控光学曲线磨床上对1A1／T2 200×6×32×4 MBD6 120／140 M75型号的砂轮进行了在线修整试验,得出了一些影响金刚笔磨损率的主要因素:火花放电时热源的能量分布状况、金刚石笔修整时的修整深度、进给量以及电源电压。相同工况下机械修整法和气中放电辅助修整法中金刚石笔的磨损率对比试验结果表明:气中放电辅助修整和机械修整有着不同的材料去除机理,它比一般机械修整更有利于提高金刚石砂轮的修整效率和降低金刚石笔的磨损量。磨削YG8硬质合金工件的试验表明,采用气中放电辅助法修整的金刚石砂轮和新的金刚石砂轮有着相近的磨削能力。