Abstract: This paper presents the processing flow and results of optical fabrication for an optical
correcting lens with a free-form surface, namely a free-form lens. Because a correcting lens has no
rotation axes of symmetry and its surface cannot be expressed by a continuity equation, its
processing technology is different with that of general aspheric lenses. The correcting lens was
firstly formed from a glass workblank with flat face using diamond abrasion wheel with spherical
shape, and then loose abrasive lapped and polished with oblique axis spherical tools to decrease the
surface roughness and increase the surface accuracy based on the measuring result after forming. At
the lapping and polishing stages, two processing methods are employed. One is to control the
processing pressure, and the other is based on dwell time. Since high precision fabrication is closely
related with high precision measuring, this paper also presents a high precision non-contact optical
measuring method based on image transforming for correcting lenses. The effectiveness of the
processing flow and technology is confirmed by an experiment in which a workblank is processed
into a satisfying correcting lens.
Abstract: Based on the analysis of various disfigurements of carbon fiber reinforced plastics
formed in drilling process, the formation model of disfigurement is built up, and analysis results
shows that the main reason of disfigurement is the exceeding cutting force. By focusing on these
problems, new-type drill—super-hard electroplated abrasive drill is developed, and some
experiments were carried out. Compared with the traditional sintered-carbide drill in drilling, the
super-hard electroplated abrasive drill has lower drilling force, better drilling quality, higher
machining efficiency, and longer life-span. A conclusion that super-hard electroplated drill is more
suitable for drilling CFRP is gained.
Abstract: Utilize the characteristic that magnetic force line may penetrate the non-magnetic
material, using the magnetic abrasive finishing (MAF) method complete to the non-magnetic small
workpiece surface precise processing. In order to enhance polishing efficiency, usually with the
magnetic particles and abrasive particles mixes together in the sinter method or the cementation
method, the cost is higher; the variety is not also complete. Therefore, use the simply mixed method
mixed the ferromagnetism iron particles, the alumina particles and the lipin, directly participates in
magnetism polishing, already obtained the good processing effect through the experiment. This
paper analysis and explanation the best experimental condition such as the granularity proportion of
the ferromagnetism iron particles and the alumina particles etc.
Abstract: Sintered NdFeB permanent magnet is widely used because of its excellent magnet
property. But there is few report of machinbility of it. This paper presents an experimental
investigation of the machining characteristics of sintered NdFeB permanent magnet using a
combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). The
EDM / USM machining mechanisms are integrated to improve the machining efficiency. During the
experiments, concentration of abrasive in the dielectric fluid is changed to explore its effect on the
material removal rate (MRR). MRR of EDM /USM, conventional EDM and tool vibration aided
EDM are compared, REWR and machined surface characteristics are also compared between them.
From the experimental results, it is concluded that the combination EDM/USM process can increase
the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate
abrasive concentration can improve its machining efficiency.
Abstract: Considering the shock between the press head and press disk in high speed lapping is more
serious, this paper proposes a new method to reduce this shock. By this method a hole is machined for
air passing on the press head axis. The topper of the hole is connecting with a pressure air resource.
Thus an air cushion between the press head bottom and press disk on the workpiece is produced. With
the distance between them reducing gradually, the damping of air cushion on the press head increases
gradually. This makes speed of the press head approaching the workpiece decrease gradually and until
reach zero. The pressure of the press head acts on the press disk increases gradually from zero to
working pressure, which can reduce the shock between the press head and workpiece effectively,
prevent weak workpiece from destroying in lapping and improve machining accuracy and quality.
This method possess the advantages of easy to carry out, simple to operate and convenient to apply.
Abstract: In order to improve the surface quality and machining efficiency for mold polishing.
Digital automatic Polishing is a good method, MasterCAM is the software that often is used for
CAM machining, path layout and building method are emphasized according to the MasterCam’s
curved surface processing path setting method, and aimed at the different curved surface use different
polishing path building method, at last, the rationality of the polishing path building was validated.
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.
Abstract: Since almost large die surfaces are free-form surfaces, currently, these are almost manually
implemented. In order to overcome this barrier, floating polishing is a feasible polishing technology.
The contact pressure between grain and workpiece is a key problem of floating polishing technology.
This paper focuses on contact pressure between grain and workpiece. At first, study the friction bound
condition between grain and workpiece by ANSYS analysis software, then, compare with the analysis
results of slip-line field theory and the test results of single grain. The results show the feasibility of
the hypothesis of full friction condition. Finally, study the contact pressure between polishing disk
and workpiece using the analysis results of single grain. The research achievements will be used for
developing the floating polishing.
Abstract: In the design of ultrasonic honing equipment, it is hard to accurately get the natural
vibration frequency of the ultrasonic vibration with the regular computing technology, which takes
great inconvenience during designing of the device and puts it into production. This paper studies
the ultrasonic vibration honing vertical equipment of φ150mm that is designed by the North
University of China and carried on the natural vibration frequency analysis and corresponded
numerical simulation, which got excellent achievement. In the paper the mathematical model is set
up, which uses the MARC software to accomplish the numerical simulation and corresponds the
vibration modal of the tool head of the devise, this paper also carries on the dynamic response
analysis and solves the related difficult problem successfully. In the end, the proof test is done to
support the theory.
Abstract: In this study, the influences of carbides and alloy additives on ground surface
characteristics of several high Chromium (Cr) steels and abrasive grains of working surface were
discussed. In the grinding using metal bonded CBN wheel, almost constant values in ground
surface roughness and high grinding ratio were shown. 5% Cr steel with Vanadium, 8% Cr steel
and 10% Cr steel showed a rougher surface than Cr steels with 3%, 4% and 5% due to the carbide
inclusion. The grinding ratio of 5%Cr steel could be raised considerably by adding sulfur to it.