Tribology and Superhydrophobicity of Laser-Controlled-Melted Alumina Surfaces with Hard Particles

JOM ◽  
2014 ◽  
Vol 66 (6) ◽  
pp. 1068-1079 ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Bharat Bhushan ◽  
B. J. Abdul Aleem ◽  
Zuhair Gaseem
Keyword(s):  
Hard Particles

scholarly journals Improving the microstructure and mechanical properties of laser cladded Ni-based alloy coatings by changing their composition: A review

2020 ◽  
Vol 59 (1) ◽  
pp. 340-351
Author(s):  
Lin Yinghua ◽  
Ping Xuelong ◽  
Kuang Jiacai ◽  
Deng Yingjun
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Composite Coatings ◽  
Single Element ◽  
Properties Of Coatings ◽  
Hard Particles ◽  
Microstructure And Mechanical Properties ◽  
Nickel Based Alloy

AbstractNi-based alloy coatings prepared by laser cladding has high bonding strength, excellent wear resistance and corrosion resistance. The mechanical properties of coatings can be further improved by changing the composition of alloy powders. This paper reviewed the improved microstructure and mechanical properties of Ni-based composite coatings by hard particles, single element and rare earth elements. The problems that need to be solved for the particle-reinforced nickel-based alloy coatings are pointed out. The prospects of the research are also discussed.

scholarly journals Structure and Properties of Coatings Made with Self Shielded Cored Wire

2016 ◽  
Vol 16 (3) ◽  
pp. 39-42 ◽  
Author(s):  
M. Gucwa ◽  
J. Winczek ◽  
R. Bęczkowski ◽  
M. Dośpiał
Keyword(s):  
Heat Input ◽  
Mining Industry ◽  
High Hardness ◽  
Properties Of Coatings ◽  
Cored Wire ◽  
Eutectic Carbides ◽  
Hard Particles ◽  
Wear And Corrosion ◽  
Flux Cored Arc Welding ◽  
Cored Wires

Abstract The welding technologies are widely used for design of protection layer against wear and corrosion. Hardfacing, which is destined for obtaining coatings with high hardness, takes special place in these technologies. One of the most effective way of hardfacing is using self shielded flux cored arc welding (FCAW-S). Chemical composition obtained in flux cored wire is much more rich in comparison to this obtained in solid wire. The filling in flux cored wires can be enriched for example with the mixture of hard particles or phases with specified ratio, which is not possible for solid wires. This is the reason why flux cored wires give various possibilities of application of this kind of filler material for improving surface in mining industry, processing of minerals, energetic etc. In the present paper the high chromium and niobium flux cored wire was used for hardfacing process with similar heat input. The work presents studies of microstructures of obtained coatings and hardness and geometric properties of them. The structural studies were made with using optical microscopy and X-ray diffraction that allowed for identification of carbides and other phases obtained in the structures of deposited materials. Investigated samples exhibit differences in coating structures made with the same heat input 4,08 kJ/mm. There are differences in size, shape and distribution of primary and eutectic carbides in structure. These differences cause significant changes in hardness of investigated coatings.

scholarly journals Numerical study of the failure of materials embedding soft to hard particles

2017 ◽  
Vol 140 ◽  
pp. 02029 ◽  
Author(s):  
Xavier Frank ◽  
Jean-Yves Delenne ◽  
Farhang Radjai
Keyword(s):  
Numerical Study ◽  
Hard Particles

scholarly journals Tool surface with a supporting plateau of hard particles for deep drawing of high alloy steel

2018 ◽  
Vol 190 ◽  
pp. 14006 ◽  
Author(s):  
Hannes Freiße ◽  
Thomas Seefeld
Keyword(s):  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Adhesive Wear ◽  
High Alloy ◽  
High Alloy Steel ◽  
Hard Particles ◽  
Aluminium Bronze ◽  
Tool Surface ◽  
Alloy Steels

Sheet metal forming normally requires the application of lubricants to protect the tool and the sheet against wear. The parts must be cleaned to remove the lubricants before joining and coating. This process step wastes energy and water resources. In the case of non-lubricated sheet metal forming, cleaning processes would not be necessary anymore and the process chain could be optimized regarding ecological and economical aspects. However, forming without lubrication leads to an intensive contact between the tool and the sheet. Thus, higher wear occurs and process reliability cannot be ensured for industrial mass production. High alloy steels are applied for mass-market products e.g. for appliances. Because of the higher strength, strain hardening and galling effects the austenitic steels are comparatively difficult to form. For dry metal forming of high alloy steels new tool concept must be developed to withstand the higher loads. In this work, a laser generated tool surface with a supporting plateau of hard particles (metal matrix composite (MMC-surface)) is presented. Spherical fused tungsten carbides were injected into the surface by laser melt injection. The metallic matrix of the composite was rejected by applying laser ablation. In consequence, the hard particles stood out of the matrix and were in direct contact with the sheet material. The surface of hard particles had a high hardness about 3000 HV and less metallic character. Cold working steel and aluminium bronze were tested as reference tool materials. Dry and lubricated forming experiments were carried out by strip drawing with bending and deep drawing of cups. Dry deep drawing of cups was not possible by using cold work tool steel. This can be traced back to the occurrence of wrinkles and cup base fracture at the same time. Applying aluminium bronze as tool material for dry metal forming resulted in high adhesive wear. Within this work the feasibility of dry metal forming of high alloy steel could be demonstrated by applying the MMC-surface whereby adhesive wear could be reduced.

scholarly journals METHODS TO COMPUTE PRESSURE AND WALL TENSION IN FLUIDS CONTAINING HARD PARTICLES

2012 ◽  
Vol 23 (08) ◽  
pp. 1240011 ◽  
Author(s):  
DEBABRATA DEB ◽  
DOROTHEA WILMS ◽  
ALEXANDER WINKLER ◽  
PETER VIRNAU ◽  
KURT BINDER
Keyword(s):  
Comparative Evaluation ◽  
Hard Spheres ◽  
Excess Energy ◽  
Attractive Potential ◽  
Wall Tension ◽  
Pressure Tensor ◽  
Colloidal Systems ◽  
Polymer Mixtures ◽  
Hard Particles ◽  
Mutual Agreement

Colloidal systems are often modeled as fluids of hard particles (possibly with an additional soft attraction, e.g. caused by polymers also contained in the suspension). In simulations of such systems, the virial theorem cannot be straightforwardly applied to obtain the components of the pressure tensor. In systems confined by walls, it is hence also not straightforward to extract the excess energy due to the wall (the “wall tension”) from the pressure tensor anisotropy. A comparative evaluation of several methods to circumvent this problem is presented, using as examples fluids of hard spheres and the Asakura–Oosawa model of colloid-polymer mixtures with a size ratio q = 0.15 (for which the effect of the polymers can be integrated out to yield an effective attractive potential between the colloids). Factors limiting the accuracy of the various methods are carefully discussed, and controlling these factors very good mutual agreement between the various methods is found.

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