Experimental Study of Geometrical Parameters of Abrasive Grains in Modeling their Cutting Edges with the Surface of Rotation

2014 ◽  
Vol 698 ◽  
pp. 529-533
Author(s):  
Alexander Petrovich Osipov ◽  
Victor Vassilevich Fedotov ◽  
Alexander Alexandrovich Zharov
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Grain Size ◽  
Penetration Depth ◽  
Apex Angle ◽  
Geometrical Parameters ◽  
Abrasive Material ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Basic Parameters

In machining with grinding, it is necessary to know values of geometrical parameters of cutting edges of abrasive grains. In this paper for modeling of cutting edges of abrasive grains with rotation surfaces based on generatrix as a power function and for division cutting edges on both plowing and forming a chip, values of basic parametersBP,NPwere obtained experimentally. The influence of abrasive grain size, sieve-shaking procedure, mechanical properties of workpiece and type of abrasive material on these parameters was determined. The restrictions of this model were designated. It is established that traditional parameters such as corner radiusrand apex angle 2θ can be used in case of microcutting with small grain penetration depth.

Grain Size Dependence of Tensile Properties in Cu-Sn Thin Foils (Experimental Study)

2015 ◽  
Vol 736 ◽  
pp. 19-23
Author(s):  
Taek Kyun Jung ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Study ◽  
Grain Size ◽  
Yield Strength ◽  
Room Temperature ◽  
Size Dependence ◽  
Yield Drop ◽  
Thin Foils ◽  
Vacuum Atmosphere

This study was carried out to investigate the effects of grain size on mechanical properties in Cu-Sn foil with a thickness of 30 um. The grain size was varied from approximately 7 um to 50 um using heat treatment at 773 K for 2 h to 24 h in a vacuum atmosphere. Tensile test was carried out at room temperature with strain rate of 1mm/min. Typical yield drop phenomenon was observed. Mechanical properties were found to be strongly affected by microstructural features including grain size. The yield strength and tensile strength gradually decreased with increasing the grain size. The strain to fracture also decreased by grain growth. These results could be explained by not only the grain size dependence of yield strength but also the ratio of thickness to grain size dependence of yield strength.

Experimental Study on Machining of Hybrid Composite Stacks Using Submerged Abrasive Waterjet Machining Process

2018 ◽  
Author(s):  
Mayur Narkhede ◽  
Sagil James
Keyword(s):  
Experimental Study ◽  
Grain Size ◽  
Hybrid Composite ◽  
Machining Process ◽  
Critical Parameters ◽  
Abrasive Waterjet ◽  
Precision Machining ◽  
Abrasive Waterjet Machining ◽  
Abrasive Grain ◽  
Waterjet Machining

The research involves experimental study on precision machining of hybrid composite stacks using Submerged Abrasive Waterjet Machining (SAWJM) process. In this study, an in-house fabricated SAWJM setup is used to machine a stack of Carbon Fiber Reinforced Polymer (CFRP) and Titanium. The effect of critical parameters including stand-off distance and abrasive grain size on the size of the cavity machined during SAWJM and Abrasive Waterjet Machining (AWJM) processes are studied. The study found that SAWJM process is capable of successfully machining CFRP/Titanium composites with high precision. The machined surface is free of thermal stresses and did not show any delamination or cracking around the edges. The study suggested that the stand-off distance and abrasive grain size has significant influence on the machining process. The cavities machined on both CFRP and titanium during SAWJM process are smaller and more circular than that produced during AWJM process. The results of this study provide deeper insight into precision machining of hybrid composite stacks.

scholarly journals Analysis and Modeling of the Micro-Cutting Process of Ti-6Al-4V Titanium Alloy with Single Abrasive Grain

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5835
Author(s):  
Łukasz Rypina ◽  
Dariusz Lipiński ◽  
Błażej Bałasz ◽  
Wojciech Kacalak ◽  
Tomasz Szatkiewicz
Keyword(s):  
Constitutive Model ◽  
High Speed ◽  
Geometric Model ◽  
Triaxial Compression ◽  
Geometrical Parameters ◽  
Machining Processes ◽  
Forming Process ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Selection Of

Modeling of material displacements in the microcutting zone is complex due to the number and interdependence of factors affecting the results of the process. An important problem in the modeling process is the selection of the constitutive model and its parameters, which will correctly describe the properties of the material under the conditions of triaxial compression, which is characteristic for the areas of the contact zone of the blade and the processed material in abrasive machining processes. The aim of the work was to develop computer models (with the use of the finite element method) of the microcutting process with a single abrasive grain, which were verified with the results of experimental tests. The paper presents the methodology of modeling the processes of microcutting with abrasive grains, whose geometrical models were created based on optical scanning methods. Observations of the microcutting process were carried out with the use of a high-speed camera and an optical profilometer. This enabled a detailed observation of the chip formation process, as well as the analysis of the surface topography of microcutting traces. The results presented in the paper indicate the convergence of the results of the numerical and experimental simulations with regard to the geometric parameters describing the scratches formed in the microcutting process and the compliance of the chip-forming process. Thus, the correctness of the selection of the constitutive model (Johnson Cook equation) and its parameters was demonstrated, as well as the correctness of the applied methodology for creating a geometric model that allowed for a reflection of the geometrical parameters of the abrasive grains that coincided with the real objects, thanks to which it was possible to reflect in detail the phenomena occurring in the vicinity of the abrasive grain tip.

Lapping of Semiconductor Wafers: An Experimental Investigation on Subsurface Damage

2009 ◽  
Author(s):  
P. F. Zhang ◽  
Z. J. Pei
Keyword(s):  
Experimental Investigation ◽  
Grain Size ◽  
Subsurface Damage ◽  
Important Process ◽  
Semiconductor Substrate ◽  
Abrasive Material ◽  
Slurry Concentration ◽  
Abrasive Grain ◽  
Vital Effects ◽  
Wafer Surfaces

Semiconductor substrate wafers are used to manufacture a variety of semiconductor devices. Lapping is an important process to obtain flat wafer surfaces. Subsurface damage, however, is unavoidably generated during the lapping process and has vital effects on wafer quality. Experiments were conducted to study the effects of several lapping parameters on subsurface damage in semiconductor substrate wafers, such as abrasive grain size, abrasive material, lapping pressure, and slurry concentration. It was found that abrasive grain size and abrasive material have significant effects on subsurface damage. Effects of lapping pressure and slurry concentration on subsurface damage were less significant.

Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel

2016 ◽  
Vol 1136 ◽  
pp. 673-677
Author(s):  
Kosaku Nomura ◽  
Naoya Takeuchi ◽  
Atsushi Kusakabe ◽  
Masahisa Chino ◽  
Hiroyuki Sasahara
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Pressure Pulsation ◽  
Grinding Wheel ◽  
Axial Vibration ◽  
Machined Surface ◽  
Plunger Pump ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Grinding Fluid

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

MICROCAST-X MAR-M-247

Alloy Digest ◽  
1995 ◽  
Vol 44 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Properties ◽  
Negative Impact ◽  
Rupture Properties

Abstract The Microcast-X process produces a substantially finer grain size that improves mechanical properties in MAR-M-247 with modest negative impact on rupture properties above 1600 F (871 C). This datasheet provides information on composition, microstructureand tensile properties as well as creep and fatigue. It also includes information on casting. Filing Code: Ni-481. Producer or source: Howmet Corporation.

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