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.

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.

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.

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.

ENHANCEMENT OF ADHESION STRENGTH AND TRIBOLOGICAL PERFORMANCE OF CVD DIAMOND FILMS ON TUNGSTEN CARBIDE SUBSTRATES WITH HIGH COBALT CONTENT VIA AMORPHOUS SiC INTERLAYERS

2019 ◽  
Vol 26 (09) ◽  
pp. 1950051
Author(s):  
YUANPING HE ◽  
YU-XIAO CUI ◽  
FANG-HONG SUN
Keyword(s):  
Tungsten Carbide ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cobalt Content ◽  
Indentation Tests ◽  
Friction Performance ◽  
Film Substrate ◽  
Amorphous Sic ◽  
And Tungsten

In this study, the diamond films are deposited on tungsten carbide substrates with 10[Formula: see text]wt.% Co via hot filament chemical vapor deposition (HFCVD). Amorphous SiC (a-SiC) interlayers with various thicknesses are fabricated between the diamond films and tungsten carbide substrates via precursor pyrolysis to promote the adhesion and friction performance of diamond films. Indentation tests are performed to evaluate the adhesion of the as-fabricated diamond films, which show that the a-SiC interlayers can greatly improve the adhesive strength between diamond films and tungsten carbide substrates with 10[Formula: see text]wt.% Co. Moreover, the thickness of a-SiC interlayer is of great importance for the effectiveness on the film–substrate adhesion enhancement. The optimum thickness of a-SiC interlayer is 1[Formula: see text][Formula: see text]m. Afterwards, ball-on-disc experiments are chosen to check the tribological properties of the as-fabricated a-SiC interlayered diamond film specimen with the optimum interlayer thickness, which exhibits lower friction coefficient than the conventional diamond film with no interlayer.

Fine Cemented Carbide Particles Prepared with Activated Tungsten Oxide

2012 ◽  
Vol 510 ◽  
pp. 619-622
Author(s):  
Xiao Ming Fu
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Tungsten Carbide ◽  
Tungsten Oxide ◽  
Experimental Results ◽  
Cemented Carbide ◽  
Carbide Particles ◽  
Better Than ◽  
And Tungsten

Fine cemented carbide in the diameter of less than 1 μm is obtained activated tungsten oxide. The samples are characterized by laser particle size analyze, electron microscope and sclerometer. The experimental results show that the size of tungsten particles and tungsten carbide prepared with activated tungsten becomes small remarkably, and coarse tungsten particles decrease. The properties of cemented carbide prepared with activated tungsten oxide are better than those of cemented carbide made with blue tungsten oxide. Especially, the hardness of cemented carbide prepared with activated tungsten oxide increases by about 7 %.

Direct Electrochemical Preparation of Cobalt, Tungsten, and Tungsten Carbide from Cemented Carbide Scrap

2016 ◽  
Vol 48 (1) ◽  
pp. 692-700 ◽  
Author(s):  
Xiangjun Xiao ◽  
Xiaoli Xi ◽  
Zuoren Nie ◽  
Liwen Zhang ◽  
Liwen Ma
Keyword(s):  
Tungsten Carbide ◽  
Cemented Carbide ◽  
Electrochemical Preparation ◽  
And Tungsten

Effect of Grain Refinement and Composition on the Wear of Cemented Carbide Cutting Tools

2013 ◽  
Vol 456 ◽  
pp. 507-511
Author(s):  
Jian Bing Cheng ◽  
Si Qin Pang ◽  
Xi Bin Wang ◽  
Qi Xun Yu
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Tool Life ◽  
Cutting Tools ◽  
Cobalt Content ◽  
Cemented Carbide ◽  
Cutting Inserts ◽  
Stereo Microscope ◽  
Different Grain Size ◽  
Flank Surface

Tool life tests of continuous cutting superalloy GH2132 were carried out by WC/Co cemented carbide cutting inserts of different grain size and cobalt content, and flank surface wear morphology of the cutting inserts were observed by ZEISS continuous zoom stereo microscope and microphotograph system. The results show that grain size and cobalt content strongly influence the cutting tool life and tool wear, grain refinement and proper cobalt content are help to improve the tool life and the wear resistance of WC/Co cemented carbide. The wear mechanisms of different grain size and cobalt content of ultrafine cemented carbide tools were adhesion and notch, among them, adhesive was the main wear mechanism at higher cutting speeds.

scholarly journals OPTIMIZATION OF CONCRETE COMPOSITIONS WITH SECONDARY INDUSTRIAL PRODUCTS

2021 ◽  
pp. 51-61
Author(s):  
M. I. NETESA ◽  
A. V. KRASNYUK ◽  
A. M. NETESA ◽  
N. A. NIKIFOROVA
Keyword(s):  
Grain Size ◽  
Iron Ore ◽  
Concrete Mixture ◽  
Processing Plant ◽  
Fine Aggregate ◽  
Iron Ores ◽  
Industrial Products ◽  
Fine Grained ◽  
Processing Plants ◽  
Ore Dressing

Purpose. Analyze scientific publications on the existing problems of environmental pollution by secondary industrial products. Search for ways to solve these issues through the rational use of concrete in construction with additives of secondary industrial products, especially fine-grained ones. Determination of rational compositions of medium-strength concrete with the minimum required consumption of cement and filler from iron ore dressing wastes of mining and processing plants. Methodology. To achieve this goal, the experience of improving the structure and properties of concrete by introducing complex additives based on secondary industrial products into its composition is analyzed. The following materials were used for the research: Portland cement CEM 41.7 from Krivoy Rog; as a large aggregate – crushed granite with a maximum grain size of 20 mm; fine aggregate – river quartz sand; mineral additives – products of concentration of iron ores of the Southern Mining and Processing Plant. The experiment was carried out on certified equipment. Control specimens with a side of 10 cm were formed. The compressive strength of concrete was determined according to a standard procedure. Based on the results of the mathematical analysis, graphical dependences of the change in the optimized characteristics on the variable parameters – the consumption of cement, the products of concentration of iron ores and the plasticizer – were built. Findings. Based on the results of testing the samples, the calculation of mathematical models of the experiment was carried out and polynomials of the third degree were obtained for the optimized parameters – the average strength of the samples and the coefficient of efficiency of using cement. The following patterns can be distinguished. The strength of concrete depends to the greatest extent on the consumption of cement in the composition of the concrete mixture and increases significantly with an increase in its content within the studied limits. With an increase in the filler content in the studied range, the strength of concrete, and, accordingly, the coefficient of efficiency of using cement increases with a decrease in the content of cement in the composition of the concrete mixture. Originality. The studies carried out make it possible to determine the main regularities of increasing the efficiency of cement use when utilizing local secondary industrial products in concrete, namely, the introduction of iron ore dressing waste from mining and processing plants as a fine-grained additive in concrete. It was found that it is possible to obtain the required low concrete strength with a significantly lower cement consumption by ensuring a rational grain size composition of the concrete mixture components. Practical value. When designing concrete compositions with a high coefficient of cement utilization, it is necessary to use the obtained research results, providing cement savings and utilizing a significant amount of fine-grained secondary industrial products.

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