Influences of Cobalt Content on the Physical and Tribological Properties of Cemented Tungsten Carbide Used in Sheet Metal Forming Application

2014 ◽  
Vol 966-967 ◽  
pp. 80-86
Author(s):  
Varunee Premanond ◽  
Onnjira Diewwanit
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Friction Coefficient ◽  
Tungsten Carbide ◽  
Cobalt Content ◽  
Steel Ball ◽  
Cemented Carbide ◽  
Average Grain Size ◽  
Stainless Steel Ball ◽  
Cemented Tungsten Carbide

The objective of this work is to investigate the tribological behavior between WC-Co cemented carbide and austenitic stainless steel under repeated rotation sliding. Influences of cobalt content of commercial grade cemented tungsten carbide on friction coefficient and material transfer phenomena have been explored. Three grades of commercial WC-Co cemented carbide with similar medium WC grain size were employed; WC-12Co, WC-14Co and WC-19Co. The average grain size were ranges between 0.85-1.1 μm and the hardness of about 86-88 HRA have been given by the material maker. The composition analysis and the average grain size of tungsten carbide have been rechecked. Furthermore, the carbide grain size distribution was recorded and the fracture toughness was calculated for each WC-Co grade. The experiments were carried out using ball on disk test. The ball was made from SUS304 grade and the disk was fabricated by 3 grades of WC-Co cemented carbide. The friction coefficient was measured under dry sliding. The characteristics of contact surfaces were explored on the ball as well as on the disk after tests to reveal the presence of a metallic transfer on the WC-Co cemented carbide disk and the wear scar on the ball. The measurement results of wear volume on the stainless steel ball disclosed that maximum wear rate was found from the stainless steel ball rub against WC-19Co tool material.

Friction Behavior of Poly (Vinyl Alcohol) Gel Against Stainless Steel Ball in Different Lubricant Media

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Yu-Song Pan ◽  
Dang-Sheng Xiong ◽  
Xiao-Lin Chen
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Vinyl Alcohol ◽  
Free Water ◽  
Steel Ball ◽  
Poly Vinyl Alcohol ◽  
Friction Behavior ◽  
Sliding Speed ◽  
Stainless Steel Ball ◽  
Pva Hydrogel

The effects of different variables on the friction coefficient of poly(vinyl alcohol) (PVA) hydrogel and stainless steel ball counterpart were investigated by a ball-on-plate friction and wear tester. Factors included lubrication condition, sliding speed, diameter of stainless steel ball, and load. It is shown that the free water in PVA hydrogel has a good lubrication on the friction counterpart. The friction coefficients have little difference between dry and lubricated conditions during the initial test stage. With the time prolonged, friction coefficient of PVA hydrogel under dry condition sharply increased within a short time. Friction coefficient decreased with increasing sliding speed and diameter of stainless steel ball. The decrease in the friction coefficient in bovine serum was 55.38% while the sliding speed increased from 45rpmto225rpm. The friction coefficient increased as the load increased, and the effect was more conspicuous at low load region.

Friction Characteristics of Poly(vinyl Alcohol) Hydrogel as an Articular Cartilage Biomaterial

2007 ◽  
Vol 330-332 ◽  
pp. 1297-1300 ◽  
Author(s):  
Yu Song Pan ◽  
Dang Sheng Xiong ◽  
Xiao Lin Chen
Keyword(s):  
Stainless Steel ◽  
Articular Cartilage ◽  
Friction Coefficient ◽  
Vinyl Alcohol ◽  
Steel Ball ◽  
Poly Vinyl Alcohol ◽  
Friction Test ◽  
Stainless Steel Ball ◽  
Lubrication Condition ◽  
Pva Hydrogel

Poly(vinyl alcohol) (PVA) hydrogel is a promising articular cartilage biomaterial. In this paper, the effects of different variable factors on the friction coefficient of Poly(vinyl alcohol) (PVA) hydrogel were investigated when sliding against stainless steel ball by ball-pan tribometer. Factors included lubrication condition, sliding speed, diameter of stainless steel ball, and load. It was shown that the free water in PVA hydrogel has an excellent lubrication on the counterparts. The friction coefficients have little difference between dry and lubricants lubrication condition at initial friction test. With the friction test time prolonged, friction coefficient of PVA hydrogel under dry condition increased rapidly. Friction coefficient decreased with the increase of sliding speed and the diameter of stainless steel ball, and increased with the increasing load. The rising rate of friction coefficient at low load region is obviously larger than that at high load region.

Effect of Frit Content on the Metal Marking and Scratching Resistance of Celadon Glaze

2016 ◽  
Vol 690 ◽  
pp. 28-32
Author(s):  
Jae Hwan Pee ◽  
Na Ri Lee ◽  
Geun Hee Kim ◽  
Yoo Jin Kim ◽  
Yoon Suk Oh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Test ◽  
Reducing Agent ◽  
Steel Ball ◽  
Resistance Test ◽  
Stainless Steel Ball

Metal marking and scratching are related to surface roughness, hardness and toughness of glaze. To improve the glaze properties, frits were added in the traditional celadon glaze and reducing firing atmosphere was controlled. Surface roughness of celadon glaze was decreased with increasing the reducing agent content (LPG flowing rate) and increasing the frits content. Though hardness of glaze without frit was increased with increasing the reducing agent content, hardness of glaze with frit was not changed extremely with increasing the reducing agent content. To evaluate the metal marking and scratching resistance, wear resistance test was used with stainless steel ball. After wear test, many metal marks and wide scratching trace were observed in the traditional celadon glaze. However, a few metal mark and scratch were observed in the celadon glaze with frit. The friction coefficient of glaze in the wear test was strongly depended on the frit contents.

Increasing the Fracture Resistance of Cemented Carbides During the Drilling of Iron Ores

1978 ◽  
Vol 100 (1) ◽  
pp. 74-76 ◽  
Author(s):  
J. Peck
Keyword(s):  
Grain Size ◽  
Tungsten Carbide ◽  
Fracture Resistance ◽  
Iron Ore ◽  
Cobalt Content ◽  
Cemented Carbide ◽  
Iron Ores ◽  
Two Parameters ◽  
Carbide Insert ◽  
And Tungsten

Investigation shows that there is a preferred cobalt content for a given hardness of a cemented carbide insert when used in a bit which is drilling iron ore. Two parameters determine the hardness of a cemented carbide: cobalt percent and tungsten carbide grain size. By manipulating these two parameters, a number of cemented carbide materials can be made which have the same hardness. Three iron-ore drilling tests have been conducted where test bits contained materials having essentially the same hardness, but where the materials were varied through a range of cobalt content and tungsten carbide grain size. Graphs are presented which depict the effect on fracture resistance of varying the cobalt content-tungsten carbide grain size. In each test, one material showed superior fracture resistance. The test bits drilled iron ores such as hematite or taconite.

Quantitative Mechanochemical Methanation of CO2 with H2O in a Stainless Steel Ball Mill

2020 ◽  
Vol 93 (9) ◽  
pp. 1074-1078 ◽  
Author(s):  
Yoshinari Sawama ◽  
Miki Niikawa ◽  
Kazuho Ban ◽  
Kwihwan Park ◽  
Shin-yo Aibara ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ball Mill ◽  
Steel Ball ◽  
Stainless Steel Ball

Focus on Carbide-Tipped Circular Saws when Cutting Stainless Steel and Special Alloys

2015 ◽  
Vol 1114 ◽  
pp. 13-21 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Federico Gobber
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Tungsten Carbide ◽  
Cobalt Content ◽  
Coarse Grained ◽  
Cemented Carbides ◽  
Grinding Wheel ◽  
Large Power ◽  
Circular Saw ◽  
Circular Saws

Circular saw blades are used exclusively for cut-off work, ranging from small manual feed operations, up to very large power fed saws commonly used for sectioning stock as it comes from a rolling mill or other manufacturing processes for long products. The teeth profile, as well as the tooth configuration are of fundamental importance for the blade performances; through a combination of blade rigidity and grinding wheel condition a good quality surface finish is attained for tools of commercial standard. The materials used for the production of circular saw blades are ranging from high speed steel to cemented carbides. In particular, cemented carbides, being characterized by high hardness and strength, are used in applications where materials with high wear resistance and toughness are required. The main constituents of cemented carbides are tungsten carbide and cobalt. Tungsten carbide imparts the alloys the necessary strength and wear resistance, whereas cobalt contributes to the toughness and ductility of the alloys. The WC-Co alloys are tailored for specific applications by the proper choice of tungsten carbide grain size and the cobalt content. The grain size of the tungsten carbide in WC-Co varies from about 40 µm to around 0.3 µm, the cobalt content from 3 to 30 wt%. The coarse grained hardmetals are mainly used in mining applications, the smallest grain size being about 3 µm and the minimum cobalt content 6 wt%. The grain size of tungsten carbide in the metal cutting industry, as well as for universal applications lies in the range of 1-2 µm. However, with the advent of near net shape manufacturing and thin walled components, the use of submicron carbide is growing, since their high compressive strength and abrasive wear resistance can be used to produce tools with a sharp cutting edge and a large positive rake angle.In this invited paper, a general overview on the actual trends in the choice of the best material when cutting special alloys will be presented and discussed. Based on the recent and past literature some examples of their up-to-date application, such as circular saws used to cut stainless steels and some high strength alloys, are talk over.

Wear Behaviour of Two Different Cemented Carbide Grades in Turning 316 L Stainless Steel

2018 ◽  
Vol 941 ◽  
pp. 2367-2372 ◽  
Author(s):  
Sara Saketi ◽  
Ulf Bexell ◽  
Jonas Östby ◽  
Mikael Olsson
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Wear Behavior ◽  
Cutting Tools ◽  
Cemented Carbide ◽  
Wear Behaviour ◽  
Binder Phase ◽  
Mechanical Wear ◽  
Cutting Insert

Cemented carbides are the most common cutting tools for machining various grades of steels. In this study, wear behavior of two different cemented carbide grades with roughly the same fraction of binder phase and carbide phase but different grain size, in turning austenitic stainless steel is investigated. Wear tests were carried out against 316L stainless steel at 180 and 250 m/min cutting speeds.The worn surface of cutting tool is characterized using high resolution scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Auger electron spectroscopy (AES) and 3D optical profiler.The wear of cemented carbide in turning stainless steel is controlled by both chemical and mechanical wear. Plastic deformation, grain fracture and chemical wear is observed on flank and rake face of the cutting insert. In the case of fine-grained, the WC grains has higher surface contact with the adhered material which promotes higher chemical reaction and degradation of WC grains, so chemical wear resistance of the composites is larger when WC grains are larger. The hardness of cemented carbide increase linearly by decreasing grain size, therefore mechanical wear resistance of the composites is larger when WC grains are smaller.

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.

The Effect of Grain Size and Cobalt Content on the Wear of Ultrafine Cemented Carbide Tools

2014 ◽  
Vol 875-877 ◽  
pp. 1344-1351
Author(s):  
Jian Bing Cheng ◽  
Si Qin Pang ◽  
Xi Bin Wang ◽  
Xi Bin Wang ◽  
Chen Guang Lin
Keyword(s):  
Grain Size ◽  
Tool Wear ◽  
Tool Life ◽  
Wear Mechanism ◽  
Wear Mechanisms ◽  
High Strength Steels ◽  
Cobalt Content ◽  
Cemented Carbide ◽  
Cemented Carbide Tools ◽  
Cutting Speeds

This work contributes to a better understanding of wear mechanisms of ultrafine cemented carbide cutting tools used in turning operation of superalloy and high strength steels at high cutting speeds. The main objective of this work is to verify the influence of grain size and the cobalt content of ultrafine cemented carbide tools on tool life and tool wear mechanism. The main conclusions are that grain size and the cobalt content of ultrafine cemented carbide tools strongly influence tool life and tool wear involve different mechanisms. The wear mechanisms of different grain size and the cobalt content of ultrafine cemented carbide tools observed on the rake face at these conditions were adhesion and notch, at the end of tool life, adhesion was the main wear mechanism at higher cutting speeds.

Effect of Microstructure on Mechanical Properties and Wear Characteristics of Cemented Tungsten Carbides

2009 ◽  
Vol 76-78 ◽  
pp. 609-612 ◽  
Author(s):  
H.Q. Sun ◽  
Rudy Irwan ◽  
Han Huang ◽  
Gwidon W. Stachowiak
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Tungsten Carbide ◽  
Removal Rate ◽  
Tungsten Carbides ◽  
Removal Rates ◽  
Wear Characteristics ◽  
Effect Of Microstructure

The effect of microstructure of cemented tungsten carbide materials on their mechanical properties and wear characteristics was investigated using nanoindentation and nanoscratch methods. The results indicated that the variation in grain size insignificantly affected the hardness, elastic modulus and friction coefficient of the work materials, but considerably influenced their removal rates. The carbide with coarser grains exhibited a much higher removal rate was obtained during scratching.

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