Advanced Materials Research Vols. 102-104

Abstract: With the increase of the quantity demanded, stone products with high quality, really artsy and diversification become more and more best-selling. The special-shaped stone machining equipments with numerical control, single machine intelligent, high speed, high efficiency and multi-function combination must be manufactured to produce these stone products. In this paper, 3D design and project optimization for special-shaped stone composite machining center are carried by Solid Works and innovative design. Model analysis of the crossbeam in this machining center is carried by ANSYS and the maximum deformation value in the crossbeam is found. The crossbeam structure is optimized by comparison and analysis. The design and manufacture of special-shaped stone combined machining center is very helpful for development of manufacturing.

Abstract: A new trajectory and uniformity was studied for single lapping process, kinematic theory analysis trajectories of the workpiece under the mode driven by swing motion. According to the theoretical analysis on lapping trajectory and simulated results, uniformity during swing driven lapping process is better than tranditional lapping process, angle rotation ratio between lapping plate and swing plate has great effect on lapping uniformity, when rotation speed of lapping plate is three times to that of swing plate, best uniformity could be gotten during lapping process.

Abstract: Because of the small thermal conductivity coefficient of Ti alloy, the heat cannot disperse timely and accumulate seriously when plunge milling Ti alloy. If the cutting parameters can not be controlled well, the phenomenon of sticking will happen easily. According to the simulation and analysis of temperature field by using finite element software ABAQUS, the influence on cutting speed and feed for the Distributing of Temperature Field about Cutting Area in Plunge Milling Ti Alloy is acquired.

Abstract: Magnetorheological flexible gasbag polishing based on the special application of magnetorheological fluid (MRF) in robotic gasbag polishing technique is a novel efficient approach in the field of mould finishing. It can control the polishing pressure by changing the magnetic force generated by MRF inside of the gasbag with the effect of variable magnetic field of electromagnetic coil. Its mathematical model is established to study the main factors influencing the material removal. The orthogonal tests are applied to analyze these important parameters. From the experimental results, it can be seen that this new approach is desirable in realizing the control of surface figure accuracy and improvement of surface quality under certain condition.

Abstract: Accelerant polishing is a new polishing technique based on the principle of diamond graphitization. It makes full use of the catalysis of transition metal such as Fe, Ti. In this paper, it researches on the trend of the graphitization of CVD diamond film at different temperature by DTA, TG, DTG and Raman spectra analysis. The results show that accelerant polishing technique can reduce the required conditions of graphitization, and carry out the graphitization reaction at a low temperature.

Abstract: In this paper, the shortcomings of the NURBS interpolator based on Taylor expansion were analyzed and shown clearly based on studying the definition and characteristic of the NURBS curve. The length function and inverse length function were employed in the length calculation of the singularity NURBS curve. The inverse length function was used to validate the length calculating of the NURBS curve. At last, a robust NURBS interpolator algorithm with singular knots was proposed.

Abstract: Development of ultra-smooth surface processing technology has great effect on the frontier technologies and defense industry, this attracts many countries to invest and highlight the research works related to ultra-smooth surface abrasive flow polishing technology. This paper gives a global review on the functional effect of ultra-Smooth surface abrasive flow polishing technology on the modern industry. Recent research achievements and machining accuracy developed by several famous universities were introduced and the principle and structure of the machining device were explained, according to the new demands for the future, the tendency of ultra-smooth surface abrasive flow polishing technology was suggested, especial emphasis on the precise polishing tool and the technology of soft contact between abrasive and workpiece.

Abstract: In recent years, the machinability of magnesium alloy is concerned more and more by the public. In this paper, a study on the cutting properties of magnesium alloy AZ91D when dry turning with kentanium cutting tools is presented. It shows the cutting force measured by a data acquisition system which is made up of Kistler9257B piezoelectric crystal sensor dynamometer, Kistler5070A10100 charge amplifier and computer. The effect of cutting parameters on cutting force was studied, and the experimental formula was built. The tool wear and chip characteristics were observed with KYKY-EM3200 electron scanning microscope and EDAX PV9900 alpha ray spectrometer, while the surface roughness of the workpiece was measured with 2205 profilometer. Results showed that the cutting depth was the main influence factor on cutting force, followed by feed rate and cutting speed . The main form of tool wear showed to be diffusive wear and adhesive wear. The feed rate had the main influence on chip form and the workpiece surface roughness, cutting speed was less effective, the cutting depth was the least.

Abstract: In order to understand the material removal mechanism in the process of chemical mechanical polishing (CMP), the states of abrasives in the slurry and on the polishing pad in CMP process have been studied by testing. It was concluded that although the abrasive in the slurry is in the form of agglomeration, but the abrasive on the polishing pad are in approximately uniform layer distribution. The different CMP slurries had been designed for CMP test of MRR. According to analyzing the test results, it was concluded that the mechanical action produced by the abrasive is the main mechanical action in wafer CMP process and the MRR mainly results from the interaction between the mechanical action of the abrasives and the chemical action of slurry. These results will provide a reliable basis for the building of abrasive trajectory model and a theoretical guide to further understanding the material removal mechanism in wafer CMP.

Abstract: To improve machining efficiency and accuracy for surface, a method of machining Non-Uniform Rational B-spline (NURBS) surface based on IGES was put forward. The algorithms for surface information processing machining path planning and real time locus interpolation involved in this method have been worked out from the research results. A prototype of the CNC milling system with “PC+PMAC motion controller” is designed by toolpath planning, coordinate transformation and acceleration-deceleration control, which using VC ++ and openGL in Windows NT + RTX system platform. The simulation experiment was conducted to test the effectiveness and accuracy of the proposed method.