Study on Fixed Abrasive Lapping Hard and Brittle Materials with Brazed Micro Powder Diamond Disk

2013 ◽  
Vol 589-590 ◽  
pp. 451-456 ◽  
Author(s):  
Quan Cheng Li ◽  
Jian Yun Shen ◽  
Cong Fu Fang ◽  
Xi Peng Xu

In this study, two different arrangement lapping disks fixed with brazed diamond pellets were used to lap silicon wafer and alumina ceramic. The effects of the surface morphology, roughness, and removal rate of workpiece caused by lapping pressure, lapping time, workpiece velocity, and disc arrangement were operated with serials experiments. The results of the researches provided guidance for fixed abrasive lapping of hard and brittle materials with the brazed micro powder diamond disk.

2014 ◽  
Vol 983 ◽  
pp. 208-213 ◽  
Author(s):  
Yong Bo Wu ◽  
Li Jun Wang

Chemical mechanical polishing (CMP) is often employed to obtain a super smooth work-surface of a silicon wafer. However, as a conventional CMP is a loose abrasive process, it is hard to achieve the high profile accuracy and lots of slurry must be supplied during CMP operations. As an alternate solution, a fixed abrasive CMP process can offer better geometrical accuracy and discharges less waste disposal. In this paper, in order to enhance the polishing efficiency and improve the work-surface quality, a novel ultrasonic assisted fixed abrasive CMP (UF-CMP) is proposed and the fundamental machining characteristics of the UF-CMP of a silicon wafer is investigated experimentally. The results show that with the ultrasonic assistance, the material removal rate (MRR) is increased, and the surface quality is improved.


2010 ◽  
Vol 426-427 ◽  
pp. 589-592 ◽  
Author(s):  
Jun Li ◽  
Yong Wei Zhu ◽  
Dun Wen Zuo ◽  
Kui Lin ◽  
M. Li

Fixed abrasive lapping and polishing (FALP) is a new machining technology and was adopted to manufacture hard brittle materials and obtain the high productivity because of fixed abrasive. The preparation process of fixed abrasive pad (FAP) was described. FALP of K9 glass, mobile panel glass and Si were investigated with fixed 5-10 µm diamond abrasives. The effect on material removal rate (MRR) and surface quality of different materials was studied. The results show that in the same FALP process conditions, Si is the highest MRR and reaches 4428 nm/min, mobile panel glass is inferior to and K9 glass is the lowest. And surface quality of mobile panel glass that surface roughness Sa is 2.10 nm and little and less damages is the best, Si is followed and K9 glass is the worst. So FALP can obtain the higher MRR and reaches several micrometers per minute and the better quality that surface roughness Sa can reach nanometer level for different materials.


Author(s):  
Bin Lin ◽  
Ping Zhou ◽  
Ziguang Wang ◽  
Ying Yan ◽  
Renke Kang ◽  
...  

Grain depth-of-cut, which is the predominant factor determining the surface morphology, grinding force, and subsurface damage, has a significant impact on the surface quality of the finished part made of hard and brittle materials. When the existing analytical models are used to predict the gain depth-of-cut in ultra-precision grinding process of silicon wafer, the results obtained become unreasonable due to an extremely shallow grain depth-of-cut, which is inconsistent with the theory of the contact mechanics. In this study, an improved model for analyzing the grain depth-of-cut in ultra-fine rotational grinding is proposed, in which the minimum grain depth-of-cut for chip formation, the equivalent grain cutting tip radius, elastic recovery deformation in cutting process, and the actual number of effective grains are considered in the prediction of the ultrafine rotational grinding of brittle materials. The improved model is validated experimentally and shows higher accuracy than the existing model. Furthermore, the sensitivity of the grain depth-of-cut to three introduced factors is analyzed, presenting the necessity of the consideration of these factors during the prediction of grain depth-of-cut in ultrafine grinding.


2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Hossein Mohammadi ◽  
John A. Patten

Ceramics and semiconductors have many applications in optics, micro-electro-mechanical systems, and electronic industries due to their desirable properties. In most of these applications, these materials should have a smooth surface without any surface and subsurface damages. Avoiding these damages yet achieving high material removal rate in the machining of them is very challenging as they are extremely hard and brittle. Materials such as single crystal silicon and sapphire have a crystal orientation or anisotropy effect. Because of this characteristic, their mechanical properties vary significantly by orientation that makes their machining even more difficult. In previous works, it has been shown that it is possible to machine brittle materials in ductile mode. In the present study, scratch tests were accomplished on the monocrystal sapphire in four different perpendicular directions. A laser is transmitted to a diamond cutting tool to heat and soften the material to either enhance the ductility, resulting in a deeper cut, or reducing brittleness leading to decreased fracture damage. Results such as depth of cut and also nature of cut (ductile or brittle) for different directions, laser powers, and cutting loads are compared. Also, influence of thermal softening on ductile response and its correlation to the anisotropy properties of sapphire is investigated. The effect of thermal softening on cuts is studied by analyzing the image of cuts and verifying the depth of cuts which were made by using varying thrust load and laser power. Macroscopic plastic deformation (chips and surface) occurring under high contract pressures and high temperatures is presented.


Author(s):  
Lijo Paul ◽  
J. Babu

Abstract Micro machining of conducting and non-conducting materials with high accuracy has great demand in industries especially in machining of ceramic, brittle materials. Abrasive Jet Machining (AJM) has shown tremendous application especially in machining of hard and brittle materials. In the present paper drilling of soda lime glass has been carried out to determine the machinability under different controlling parameters. A set of L9 series experiments were carried out by varying process parameters such as Stand Off Distance (SOD), Silicon carbide abrasive particles mesh sizes and jet pressure. Material Removal Rate (MRR) and Radial Over Cut (ROC), were taken as the output responses and are optimised with multi objective optimisation.


2005 ◽  
Vol 291-292 ◽  
pp. 139-144 ◽  
Author(s):  
X. Kang ◽  
Junichi Tamaki ◽  
Akihiko Kubo ◽  
Ji Wang Yan ◽  
Toshirou Iyama

For the purpose of investigating the effect of cutting edge truncation on ground surface morphology, several kinds of hard and brittle materials used for optical devices, borosilicate glass, glass quartz, crystal quartz and sapphire, are plunge ground with a SD600 metal-bonded grinding wheel, the cutting edges of which are truncated so as to be aligned with the height level of the grinding wheel working surface, after electrocontact discharge truing and dressing. It is found that an improvement of roughness can be obtained for every material investigated, although the degree of roughness improvement depends on the kind of material. Ductile-mode grinding is most likely to be realized in the case of crystal quartz.


Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 81
Author(s):  
Yanhua Zou ◽  
Ryunosuke Satou ◽  
Ozora Yamazaki ◽  
Huijun Xie

High quality, highly efficient finishing processes are required for finishing difficult-to-machine materials. Magnetic abrasive finishing (MAF) process is a finishing method that can obtain a high accuracy surface using fine magnetic particles and abrasive particles, but has poor finishing efficiency. On the contrary, fixed abrasive polishing (FAP) is a polishing process can obtain high material removal efficiency but often cannot provide a high-quality surface at the nano-scale. Therefore, this work proposes a new finishing process, which combines the magnetic abrasive finishing process and the fixed abrasive polishing process (MAF-FAP). To verify the proposed methodology, a finishing device was developed and finishing experiments on alumina ceramic plates were performed. Furthermore, the mechanism of the MAF-FAP process was investigated. In addition, the influence of process parameters on finishing characteristics is discussed. According to the experimental results, this process can achieve high-efficiency finishing of brittle hard materials (alumina ceramics) and can obtain nano-scale surfaces. The surface roughness of the alumina ceramic plate is improved from 202.11 nm Ra to 3.67 nm Ra within 30 min.


2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.


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