Removal mechanism and surface quality of crystal semiconductor materials in scratching tests with Berkovich indenter

2020 ◽  
Vol 105 ◽  
pp. 104746 ◽  
Author(s):  
Cheng Zhang ◽  
Hongtao Zhu ◽  
Zhaoliang Jiang ◽  
Chuanzhen Huang ◽  
Jun Wang
Keyword(s):  
Surface Quality ◽  
Semiconductor Materials ◽  
Berkovich Indenter ◽  
Removal Mechanism

Study on Removal Mechanism and Surface Quality of High Volume Fraction SiCp/Al Composites Based on Meso-scale

2021 ◽  
Author(s):  
Po Jin ◽  
Qi Gao ◽  
Quanzhao Wang ◽  
Wenbo Li
Keyword(s):  
Particle Size ◽  
Surface Quality ◽  
Feed Rate ◽  
Volume Fraction ◽  
High Volume ◽  
Milling Process ◽  
Subsurface Damage ◽  
High Volume Fraction ◽  
Removal Mechanism

Abstract The milling process of SiCp/Al composites with high volume fraction and large particle size has been studied in this paper. The stress and strain distribution of SiC reinforced particles and the removal mechanism of the material are analysed. The effects of milling depth and feed per tooth on surface quality were analysed. The effect of feed per tooth on the thickness of subsurface damage layer is revealed. The results show that in the end milling process of high volume fraction SiCp/Al composites, the blade diameter is larger relative to the particle size, which leads to the main removal forms of particle size: extrusion crushing and rolling crushing. The surface defects of the machined workpiece mainly include cavity, crack and delamination caused by extrusion of aluminum matrix. The surface quality of the machined workpiece can be improved by increasing the milling depth appropriately. The increase of the feed rate of each tooth will lead to the increase of the surface defect of the machined workpiece and the deterioration of the surface quality. When the feed rate per tooth increases from 4 to 8 μm, the thickness of subsurface damage increases from 47.7 to 60.5 μm. It is found that the ratio between the minimum cutting thickness of SiCp/Al composites and the radius of the cutting edge should be less than or equal to 4%.

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

scholarly journals Face Grinding Surface Quality of High Volume Fraction SiCp/Al Composite Materials

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xu Zhao ◽  
Yadong Gong ◽  
Guiqiang Liang ◽  
Ming Cai ◽  
Bing Han
Keyword(s):  
Friction Coefficient ◽  
Surface Morphology ◽  
Surface Quality ◽  
Volume Fraction ◽  
High Volume ◽  
Spindle Speed ◽  
High Volume Fraction ◽  
Machining Parameters ◽  
Al Composite

AbstractThe existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology. However, the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied. In this study, 32 SiCp/Al specimens with a high volume fraction were prepared and their machining parameters measured. The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed. The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force, friction coefficient, and roughness parameters as the evaluation standards. The best grinding parameters were obtained by analyzing the surface morphology. The results show that, a higher spindle speed should be chosen to obtain a better surface quality. The final surface quality is related to the friction coefficient, surface roughness, and fragmentation degree as well as the quantity and distribution of the defects. Lower feeding amount, lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality. Lower feeding amount, higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality. This study proposes a systematic evaluation method, which can be used to guide the machining of SiCp/Al composites with a high volume fraction.

Simulation and Productive Practice of 60 Tons Huge Rectangular Ingot by Wind Cooling

2011 ◽  
Vol 233-235 ◽  
pp. 2714-2717
Author(s):  
Xin Gang Ai ◽  
Sheng Li Li ◽  
Dong Wei Zhang ◽  
Nan Lv ◽  
Jun Tao
Keyword(s):  
Mathematical Simulation ◽  
Surface Quality ◽  
Solidification Time ◽  
Special Method ◽  
Cooling Process ◽  
Heavy Plate ◽  
Simulation Results

Huge rectangular ingots becomes crying needs in the condition of lots of heavy plate mills more than 5m have been in operation. In this paper, a special method of wind cooling outside mould has been presented and applied to produce 60t rectangular ingot. Mathematical simulation results tell us that by wind cooling, the solidification time of the 60t ingot can be shortened by 67 minutes, internal soundness can be ensured. The wind cooling process can obviously improve microstructure and preventing skull patch by increasing the thickness of solidified shell. A 60 tons huge rectangular ingot is successfully produced by wind cooling, the surface quality of is very well and the internal soundness should be improved further.

Synthesis of high-temperature thermally expandable microcapsules and their effects on foaming quality and surface quality of foamed ABS materials

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 519-527
Author(s):  
Wei Gong ◽  
Xianglin Pei ◽  
Xiaogang Yin ◽  
Daming Ban ◽  
Hai Fu ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Quality ◽  
Volume Fraction ◽  
Crosslinking Agent ◽  
Acrylonitrile Butadiene Styrene ◽  
Foaming Agent ◽  
Blowing Agent ◽  
Good Surface ◽  
Butadiene Styrene

AbstractIn this paper, acrylonitrile and hydroxypropyl acrylate are used as the binary polymerization monomers, and isooctane is used as the foaming agent to prepare high-temperature thermally expandable microcapsules. Analysis of the effect of blowing agent and crosslinking agent on the expansion properties of high-temperature thermally expandable microcapsules, the effects of foaming agent azodicarbonamide (ADCA) and micro-expansion capsule on the surface quality and foaming quality of foamed acrylonitrile–butadiene–styrene (ABS) products were investigated. The foamed product prepared by the high-temperature microcapsule has a good surface quality, the gloss is 52.3, the cell is not easily deformed, and the volume fraction is 4%; the foamed ABS/ADCA material has poor cell uniformity, the cell is easily deformed, the volume fraction is 6.5%, the surface quality is poor, and the gloss is only 8.7.

Laser polishing to improve the surface quality of CoCr and Ti6AL4V additively manufactured parts

2017 ◽  
Author(s):  
Wojciech S. Gora ◽  
Yingtao Tian ◽  
Marcus Ardron ◽  
Philip Prangnell ◽  
Nicholas J. Weston ◽  
...  
Keyword(s):  
Surface Quality ◽  
Laser Polishing

Study on the Surface Quality of LiNbO3 Wafer by CMP

2004 ◽  
Vol 259-260 ◽  
pp. 644-647 ◽  
Author(s):  
Tong Xing ◽  
Ju Long Yuan ◽  
W. Li ◽  
Shi Ming Ji ◽  
L.B. Zhang ◽  
...  
Keyword(s):  
Surface Quality

Study on the Behavior of the Cast-Iron Bonded Grinding Wheel to Machining Properties of Hard and Brittle Materials

2007 ◽  
Vol 24-25 ◽  
pp. 229-232
Author(s):  
S.L. Ma ◽  
Wei Li ◽  
Cong Rong Zhu ◽  
J. Zhang ◽  
H.C. Ye
Keyword(s):  
Grain Size ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Surface Quality ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Different Grain Size ◽  
Grinding Efficiency ◽  
Machining Properties

Tungsten carbide which is a hard and brittle material was ground by cast-iron bonded diamond wheel with ELID (Electrolytic In-Process Dressing) technique, for the purpose of getting high efficiency, super-precision machining. Three kinds of cast-iron bonded diamond wheels with different grain size were adopted to get different grinding efficiency and surface quality of workpieces. The grinding properties of cast-iron bonded grinding wheels with different grain size and the ground surface quality of tungsten carbide are discussed in this paper. The experiment results indicate that, under the same feeding amount, the grinding efficiency of the wheel with bigger grain size is higher, and it could make the dimension accuracy of the workpiece controllable, but the wheel with smaller grain size could get better ground surface quality. The two grinding phases are decided by the ratio between the size of abrasive grain and the thickness of the oxide layer on the grinding wheel.

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