Surface re-orientation caused on metals by abrasion—its nature, origin and relation to friction and wear

1958 ◽  
Vol 247 (1250) ◽  
pp. 353-368 ◽  
Keyword(s):  
Fibre Orientation ◽  
Normal Load ◽  
Abrasive Particle ◽  
Electron Diffraction Investigation ◽  
Abrasive Particles ◽  
Emery Paper ◽  
Axis Parallel ◽  
First Time ◽  
Rotational Slip ◽  
Increasing Load

No adequate study of the surface structure of abraded poly crystalline metals has been made hitherto. The present electron-diffraction investigation of unidirectionally abraded beryllium and magnesium elucidates for the first time the characteristic nature and the origin of the fibre texture caused by abrasion, particularly its relation to the friction coefficient and the wear. The effects of a wide variety of conditions of load, speed, temperature and abrasive-particle size are determined. The main fibre orientation developed is of [001] type, the axis being inclined by an angle δ away from the outward normal, towards the direction from which the abrasive particles came. For beryllium δ is about 21°, the fibre axis being then along the resultant of the normal load W and the tangential frictional force F , at tan-1 μ = tan -1 0.38 to the normal. For magnesium δ= 22° and μ = 0*40. This main oblique fibre orientation is clearly a compres­sion texture, the (0001) slip lamellae becoming oriented normal to the compression axis. A very weak tendency of azimuthal preference round this axis, with <100> normal to the abrasion direction, was also observed in a few cases. With increasing load (above 1 Kg/cm 2 , using 0000 emery paper) on beryllium, in addition to the above main oblique texture the surface regions showed an increasing proportion of metal having a [001] fibre orientation with its axis normal to the surface, associated with the progressively greater amount of metal removed by shearing. Similar oblique and normal [001] fibre textures are developed by abrasion on single-crystal beryllium surfaces, showing clearly the extent of the lattice fragmentation. The region of transition to the underlying undisturbed crystal lattice indicates by its form that the deformation process involves flexural rotational slip on (0001), i. e. rotational slip on (0001) with simultaneous flexure of the slip lamellae about an axis parallel to (0001) not limited to the usual <210> direction.

scholarly journals The Surface Condition of Ni-Cr after SiC Abrasive Blasting for Applications in Ceramic Restorations

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5824
Author(s):  
Weronika Czepułkowska-Pawlak ◽  
Emilia Wołowiec-Korecka ◽  
Leszek Klimek
Keyword(s):  
Surface Condition ◽  
Abrasive Particle ◽  
Surface Profile ◽  
Abrasive Particles ◽  
Dental Restorations ◽  
Large Width ◽  
Ceramic Restorations ◽  
The Impact ◽  
Abrasive Size ◽  
Abrasive Blasting

Abrasive blasting is a process widely used in dentistry. One of the uses is the development of metal surfaces for connections with ceramics in fixed prosthetic restorations. The purpose of this paper was to check how the rough surface profile (width, height, and depth on unevenness) impacts the surface’s condition, like its wettability and percentage of stuck abrasives. The Ni-Cr alloy surface was abrasive blasted by silicon carbide with the various pressure parameters (0.2, 0.4, and 0.6 MPa) and abrasive particle sizes (50, 110, and 250 µm). Cleaned surfaces were examined for roughness, wettability, and percentage of stuck abrasive particles on the surface. The surface after abrasive blasting using 110 µm of abrasive size and 0.4 MPa pressure has the best wettability results. The width of unevenness may cause it. When the unevenness has too small or too large width and depth, the fluids may not cover the entire cavities because of locking the air. The surface condition of dental alloys directly affects metal–ceramic connection strength. The knowledge about the impact of the abrasive blasting parameters on the bond strength will allow one to create durable dental restorations.

scholarly journals Abrasive jet micro-machining of metals

2021 ◽  
Author(s):  
Sayeed Ally
Keyword(s):  
Normal Incidence ◽  
Impact Angle ◽  
Oblique Impact ◽  
Micro Machining ◽  
Surface Evolution ◽  
Abrasive Particles ◽  
Micro Features ◽  
Semi Empirical ◽  
First Time ◽  
Good Agreement

Abrasive jet micro-machining is a process that utilizes small abrasive particles entrained in a gas stream to erode material, creating micro-features such as channels and holes. Erosion experiments were carried out on aluminum 6061-T6, Ti-6A1-4V alloy, and 316L stainless steel using 50 μm A1₂O₃ abrasive powder launched at an average speed of 106 m/s. The dependence of erosion rate on impact angle was measured and fitted to a semi-empirical model. The erosion data was used in an analytical model to predict the surface evolution of unmasked channels machined with the abrasive jet at normal and oblique incidence, and masked channels at normal incidence. The predictions of the model were in good agreement with the measured profiles for unmasked channels at normal and oblique impact, and masked channels in at normal incidence up to an aspect ratio (channel depth/width) of 1.25. For the first time, it has been demonstrated that the surface evolution of features machined in metals can be predicted.

Material Removal and Application by Chemical Impact Reaction in Nano-Abrasive Jet Polishing

2013 ◽  
Vol 631-632 ◽  
pp. 550-555
Author(s):  
Wen Qiang Peng ◽  
Sheng Yi Li ◽  
Chao Liang Guan ◽  
Xin Min Shen
Keyword(s):  
Material Removal ◽  
Abrasive Particle ◽  
Precision Machining ◽  
Optical Surface ◽  
Polishing Process ◽  
Abrasive Particles ◽  
Mechanical Process ◽  
Abrasive Jet Polishing ◽  
Ultra Precision ◽  
Machining Properties

Material removed by mechanical process inevitably causes surface or subsurface damage containing cracks, plastic scratch, residual stress or dislocations. In nano-abrasive jet polishing (NAJP) the material is removed by chemical impact reaction. The chemical impact reaction is validated by contrast experiment with traditional lap polishing process in which the material is mainly removed through mechanical process. Experiment results show the dependence of the abrasive particles on the choice of materials. Even if the abrasive particle and the workpiece are composed of similar components, the machining properties are remarkably different due to slight differences in their physical properties or crystallography etc. Plastic scratches on the sample which was polished by the traditional mechanical process are completely removed by NAJP process, and the surface root-square-mean roughness has decreased from 1.403nm to 0.611nm. The NAJP process will become a promising method for ultra precision machining method for ultrasmooth optical surface.

scholarly journals Annular Surface Micromachining of Titanium Tubes Using a Magnetorheological Polishing Technique

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 314 ◽  
Author(s):  
Wanli Song ◽  
Zhen Peng ◽  
Peifan Li ◽  
Pei Shi ◽  
Seung-Bok Choi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Rotation Speed ◽  
Abrasive Particle ◽  
Internal Surface ◽  
Abrasive Particles ◽  
High Magnetic Field Strength ◽  
Titanium Alloy Tube

In this study, a novel magnetorheological (MR) polishing device under a compound magnetic field is designed to achieve microlevel polishing of the titanium tubes. The polishing process is realized by combining the rotation motion of the tube and the reciprocating linear motion of the polishing head. Two types of excitation equipment for generating an appropriate compound magnetic field are outlined. A series of experiments are conducted to systematically investigate the effect of compound magnetic field strength, rotation speed, and type and concentration of abrasive particles on the polishing performance delivered by the designed device. The experiments were carried out through controlling variables. Before and after the experiment, the surface roughness in the polished area of the workpiece is measured, and the influence of the independent variable on the polishing effect is judged by a changing rule of surface roughness so as to obtain a better parameter about compound magnetic field strength, concentration of abrasive particles, etc. It is shown from experimental results that diamond abrasive particles are appropriate for fine finishing the internal surface of the titanium-alloy tube. It is also identified that the polishing performance is excellent at high magnetic field strength, fast rotation speed, and high abrasive-particle concentration.

Roles of Surfactant Molecules in Post-CMP Cleaning

2005 ◽  
Author(s):  
Dedy Ng ◽  
Milind Kulkarni ◽  
Hong Liang
Keyword(s):  
Surfactant Concentration ◽  
Substrate Surface ◽  
Wafer Surface ◽  
Particle Removal ◽  
Abrasive Particles ◽  
Effective Particle ◽  
Cleaning Solution ◽  
Before And After ◽  
First Time ◽  
Hydrophilic Particles

One major concern in post-CMP cleaning is particles contamination on the substrate surface after the CMP process. These particles can be abrasive particles from the slurry, debris from pad material, and particles of film being polished. The cleaning method used in this study is direct contact of the substrate surface and brush sweeping. To enhance the cleaning process, an anionic surfactant is added in the cleaning solution. In order to understand effects of surfactant molecules on post-CMP cleaning, for the first time, we use a tribological approach over a range of surfactant concentration and temperature. In this regard, we observe how the surfactant behavior before and after it reaches the critical micelles concentration (cmc). Experimental results show that increase in surfactant concentration can promote bilayer interaction of micelles on the hydrophilic particles. Based on our study, we propose an interactive explanation of surface molecules with the wafer surface and nanoparticles through friction. This understanding will serve as a guide on how much surfactant should be added in order to achieve effective particle removal.

Friction Behavior of CMP Slurries Based on Novel Organic Particles

2005 ◽  
Author(s):  
Yuzhuo Li ◽  
Ning Wang
Keyword(s):  
Removal Rate ◽  
Dielectric Materials ◽  
Friction Behavior ◽  
Abrasive Particles ◽  
Added Benefit ◽  
Increasing Demand ◽  
Organic Particles ◽  
Physical And Chemical ◽  
The Impact ◽  
First Time

With the integration of copper as interconnect and low k materials as dielectric, the CMP community is facing an ever increasing demand on reducing defectivity without scarifying production throughput. One such strategy is to significantly lower the polishing pressure to below 1 psi. Such a move has placed tremendous challenges to the tool manufactures, consumable suppliers (especially the slurry vendors), and end-users. It is a challenge to remain the high throughput (MRR and selectivity) at low down force without using harsh abrasives. For the first time, we recently report the use of novel hydrophilic organic particles for metal CMP. Unlike conventional abrasive particles such silica or alumina, these unique particles are designed to specifically interact with the metal surface to be polished and significantly modify the rheological behavior of the slurry. The obvious advantage of using such particles is the reduction of defects during CMP. The consequence of using such particles is also its ability to provide unsurpassed high selectivity in removal rate for copper over barrier and dielectric materials due to their weak interaction with these particles. The added benefit for slurry that uses such particles is to allow CMP process conducted at a lower down force without compromising the throughput. In this talk, some basic physical and chemical characteristics of the particles and slurry will be first presented. The friction beavior of these new slurries in relation to conventional slurries on blanket wafers will be discussed. The impact of particle hydrophobicity on the friction behviors of the slurries will be explored.

scholarly journals Investigation of the Design and Fault Prediction Method for an Abrasive Particle Sensor Used in Wind Turbine Gearbox

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 365
Author(s):  
Le Zhang ◽  
Qiang Yang
Keyword(s):  
Wind Turbine ◽  
Design Method ◽  
Abrasive Particle ◽  
Prediction Method ◽  
Fault Prediction ◽  
Superior Performance ◽  
Lubricating Oil ◽  
Operation Performance ◽  
Wind Turbine Gearbox ◽  
Abrasive Particles

The gearbox is a key sub-component of a wind power generation system with high failure rate leading to shutdowns. By monitoring the abrasive particles in the lubricating oil when the gearbox is running, any abnormal condition of the gearbox can be found in advance. This information may be used to improve the operational safety of the wind turbine and reduce losses because of shutdowns and maintenance. In this paper, a three-coil induction abrasive particle sensor is designed based on the application of high-power wind turbine gearbox. The performance of the sensor and the design method of the detection circuit are described in detail, and the sensor operation performance used in the 2 MW wind turbine is verified. The results show that the sensor has superior performance in identifying ferromagnetic abrasive particles above 200 μm and plays a good role in status monitoring and fault prediction for the gearbox.

Wear of Abrasive Particles in Slurry During Lapping

2014 ◽  
Author(s):  
James T. Lehner ◽  
Christopher A. Brown
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Design Of Experiments ◽  
Abrasive Particle ◽  
Steel Ball ◽  
Abrasive Particles ◽  
Individual Variable ◽  
Stainless Steel Ball ◽  
Experimental Runs

Changes in abrasive particle size, shape, and sharpness are studied in multi-axis lapping of sealing regions of stainless steel ball valves. Twelve experimental runs, investigating changes in the abrasive particle as a function of lapping load and motion, are performed during lapping. The influence of changes in the lapping load and motion are investigated using design of experiments. Changes in the size, shape, and sharpness of the abrasive particle are influenced by the load and by the motion of the seats and balls of the valves. Combinations of lapping load and motions, as opposed to any individual variable, tend to dominate the influence on the changes in the abrasive particle.

Vibration Polishing Edge Preparation for Cemented Carbide Inserts

2012 ◽  
Vol 201-202 ◽  
pp. 1174-1177
Author(s):  
Jiao Wang ◽  
Hao Wang ◽  
Ai Bing Yu
Keyword(s):  
Cutting Tools ◽  
Abrasive Particle ◽  
Optical Microscope ◽  
Cutting Edge ◽  
Cemented Carbide ◽  
Abrasive Particles ◽  
Cemented Carbide Tool ◽  
Carbide Inserts ◽  
Edge Preparation ◽  
Cemented Carbide Inserts

Micro-cracks on cutting edge will cause early breakages on cutting tools, accelerate tool wear and reduce cemented carbide tool life. Edge preparation can improve the cutting edge quality. Vibration polishing experiments were carried out for cemented carbide inserts edge preparation. Inserts and fixtures were put into the vibration polishing equipment which forced abrasive particles to collide and polish inserts. Edge preparation for fixed type insert and free type insert were compared with three sizes of abrasive particles. And the polishing time was changed for each testing cases. Experiments were carried out by altering polishing time, abrasive particle size and tool clamping way to determine the optimum technology of vibration polishing edge preparation. The experimental results showed that edge breakage numbers of insert significantly reduced. Smooth and round cutting edges were observed by optical microscope after edge preparation. Edge preparation experiments prove that edge preparation can change the cutting edge geometry and improve the cutting tool quality.

Method for Direct Parametric Analysis of Nonlinear Forced Response of Bladed Discs With Friction Contact Interfaces

2004 ◽  
Author(s):  
E. P. Petrov
Keyword(s):  
Parametric Analysis ◽  
Large Scale ◽  
Normal Load ◽  
Forced Response ◽  
Finite Element Models ◽  
Contact Interface ◽  
Friction Contact ◽  
Interface Parameters ◽  
First Time ◽  
Contact Parameters

An effective method for direct parametric analysis of periodic nonlinear forced response of bladed discs with friction contact interfaces has been developed. The method allows, for the first time, forced response levels to be calculated directly as a function of contact interface parameters such as the friction coefficient, contact surface stiffness (normal and tangential coefficients), clearances, interferences, and the normal stresses at the contact interfaces. The method is based on exact expressions for sensitivities of the multiharmonic interaction forces with respect to variation of all parameters of the friction contact interfaces. These novel expressions are derived in the paper for a friction contact model, accounting for the normal load variation and the possibility of separation-contact transitions. Numerical analysis of effects of the contact parameters on forced response levels has been performed using large-scale finite element models of a practical bladed turbine disc with underplatform dampers and with shroud contacts.

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