Advanced Materials Research Vol. 1027

Abstract: Diamond is a kind of ultra-hard and difficult-to-machine material. By means of the graphitization of diamond, dynamic friction polishing (DFP) technology is used to achieve a high-efficiency material removal of diamond. The polishing plate of DFP plays a key role in the process of polishing, and catalytic metal with unpaired d electrons is considered as ideal polishing material. To discuss and verify the feasibility that amorphous alloy can be used to polish CVD diamond film by DFP, Fe based amorphous alloy was prepared by mechanical alloying method and spark plasma sintering technology. The results showed that diamond film got a higher removal and a better polishing effect. This work provided a new selection for the polishing plate used for DFP of diamond.

Abstract: Magnetorheological finishing (MRF) is an advanced machining technology can achieve high efficiency and smoother surfaces. This study discusses the material removal mechanism of MRF, and proposes a kind of magnetorheological fluid with the nano-diamond abrasives. A series of experiments on the BK7 optical glass were conducted to investigate effects of the concentration of nano-diamond abrasives on surface quality and removal efficiency.

Abstract: The main effects in centrifugal barrel finishing result from the impact of the mutual impacts, the interaction of extrusion, the rotation shear and the sliding force, it can’t be calculated that the force created by the collision among the media and the velocity of the media at present. It is concluded that the velocity of the media is 5.107m/s through simulating the motion in EDEM, which is 2.28% error with theoretical calculation. Using orthogonal experiment to analyze different sizes and material media, it is concluded that media size mainly affects the tangential force, normal force and rolling friction.

Abstract: Flexible displays will become the mainstream display of next generation, so the manufacturing technology of the flexible display substrate is one of very important technologies. In this paper, according to orthogonal design, the composition selection and optimization of chemical mechanical polishing (CMP) slurry based on alumina abrasive had been done in CMP ultra-thin stainless steel surface by a lot of tests. The CMP slurry based on alumina abrasive for ultra-thin stainless steel surface had been obtained. According to the test results, the material removal rate (MRR) is about 177 nm/min and the surface roughness (Ra) is about 0.018μm.

Abstract: For subsurface crack detection of single crystal SiC wafer, this paper proposed a cross-sectional cleavage detection method and compared with traditional cross-sectional sample preparation method. The characteristics and detection results of two cross-sectional sample preparation methods were compared and the subsurface crack characteristics in SiC wafer grinding were researched. The results show that the configurations and depth of subsurface cracks measured by two cross-sectional sample preparation methods were similar. The cross-sectional cleavage sample preparation method is simpler and more rapid in subsurface crack detection. The subsurface crack system of single crystal SiC wafer grinding mainly includes lateral crack and median crack.

Abstract: To solve the precision manufacturing of thin-walled irregular-shaped workpiece, the MR fluids flexible fixture was designed and the simulation of device with compression structure was carried out to obtain performance parameters of device for optimizing the device. Then, some experimental test was implemented to verify the feasibility of device. The simulation and experimental results show that the current and coil turns have a great influence on magnetic field, and the shear stress of MR fluids are related with magnetic field and external compression force. The experimental results are in good agreement with simulation ones.

Abstract: A new kind of miniature air compressor is proposed in this paper. This compressor can produce both compressed air and vacuum. The system structure, operating principle and experimental characteristics of the novel miniature air compressor are described in detail. The experimental results prove that the shift between air compressor mode and vacuum pump mode is possible and the design of system structure is appropriate.

Abstract: Aiming at the problem that the tracking frequency range of ultrasonic power is fixed, and the accuracy of tacking frequency is low, the tactics of digital phase-locked loop frequency tracking technology combined with changing step searching circuit peak is proposed. The frequency tracking is achieved by combining the advantages of digital phase-locked loop frequency tracking technology with changing step searching circuit peak, building the digital phase detector circuit and current effective value converter circuit, taking the feedback of sampling the phase and circuit peak as basic of frequency tracking. Build the simulating model in Multisim. The experiment results show that composite frequency tracking strategy can effectively achieve frequency tracking and dynamically lock transducer multi-modal resonance.

Abstract: In order to solve the problem of efficient and accurate tool change in vibration system, horn with a conical hole and a center via hole which connects tool is proposed. In connection with the shape of the horn, an equivalent model of the horn is built up. Based on the transmission matrix method, the frequency equation and magnification factor of the horn is deduced. And the finite element method was employed to verify the derived formulas. Compared the simulation results with the theoretical results, the derived formulas can be applied to design the complex horn.

Abstract: The components of spindle system are key components in ultra precision machine tool. According to the characteristics of the machining process of vertical hydrostatic spindle system for ultra-precision fly cutting machine, the mass- stiffness model of the spindle system is established. This paper describes a system for the analysis of the spindle system under the action of external shocks. The use of the state space method is discussed and an example is given. The influence law of vibration frequency is obtained for the various mass and stiffness value of the spindle system components.