Papers by Author: Feng Chen

Abstract: To obtain high surface quality and high finishing efficiency in machining SUS440 stainless steel, a novel machining technology employing a semi-fixed abrasive plate (SFAP) is adopted. The SFAP is developed for preventing lapped surface from damage caused by larger particles (from grain size dispersion or from outside of processing area, larger particles could bring uneven load distribution on processing region). The effects of different parameters on the surface quality and the material removal rate (MRR) of SUS440 stainless steel which is lapped by SFAP are investigated in this paper. The control parameters of the lapping process include the lapping time, the load, the rotating speed of the lapping plate, and etc. SFAP of 800# SiC abrasive used, Experimental results indicate that SFAP can avoid the large scratch effectively and the surface roughness (Ra) of the workpiece could be improved from 250 nm to 50 nm in 12 Min. A nearly mirror-like surface can be obtained.

Abstract: The most typical example of hard and brittle material is advanced ceramics, for its ultra-precision machining difficulty and wide applications, now it becomes a focus of attention. Semi-fixed abrasive plate (SFAP) is newly developed tool for machining advanced ceramics; As a result of SFAP abrasion, a gradual change takes place in the SFAP topography to influence on machining results and productivity. The paper shows experiment procedures to evaluate SFAP abrasion rate and workpiece material removal. The results of experiments are discussed and analyzed, it indicates that wet status of SFAP have great influences on the removal rate and SFAP abrasion. Compared with dry status of SFAP, wet status of SFAP can achieve higher processing efficiency.

Abstract: In plane lapping, workpiece material removal and lapping wheel wear has been influenced each other and should be evenly distributed. Only required a flat lapping wheel, it could be obtained with flat workpieces and small thickness deviations. Therefore, the choice of the truing operation has an important effect on the quality of the lapping wheel and on the flatness of product. This is a way that using truing ring to true lapping wheel in certain eccentricity plane lapping system　to acquire the flatness. The kinematics of certain eccentricity plane lapping for uniformity of processing is analyzed in this paper firstly. Then different sizes and locations of truing ring that influences truing on the flatness of lapping wheel has evaluated and simulated. Lastly, a suitable truing operation of certain eccentricity plane lapping is proposed.

Abstract: The amorphous Ni-Pd-P alloy films with superior property have good heat conductivity and wear performance. They are widely used in the protecting coating. Copper has been chosen to be a substrate material of the produce of amorphous Ni-Pd-P alloy films with its unique electrical properties. The precision lapping technology for the copper substrate using semi-bonded abrasive grinding plate is studied in this paper. The influences of the different lapping parameters on the surface roughness, material removal rate on copper substrate surface formation in the precision lapping process are both discussed. Experimental results indicate that the copper substrate can be efficiently processed by 800# SiC semi-bonded abrasive grinding plate of, and the initial roughness of a machined surface could be improved from 0.553μm Ra to 0.28μm in 10min, yielding a ideal rarely scratch surface.

Abstract: In this paper, mixed slurries containing silica abrasives and polystyrene (PS) polymer particles in deionized water at pH 10.5 have been evaluated for silicon wafer polishing. By applying the theory of electric double layer model, the effect of the particle interactions in mixed slurry is investigated. Zeta potential measurements and TEM images have been used to show the formation of composite particles. The polishing mechanism with composite particles slurries is discussed. Polishing experiments with the mixed slurries formed by coating smaller (~30nm) abrasives onto softer and larger (~2000nm) polymer particles have shown the superior characteristic with higher removal rate and high surface quality.