Machining and Wear of High-Alumina Ceramics for Structural Applications

2009 ◽  
Vol 409 ◽  
pp. 137-144 ◽  
Author(s):  
Stojana Veskovic-Bukudur ◽  
Tanja Leban ◽  
Milan Ambrozic ◽  
Tomaž Kosmač
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Direct Relationship ◽  
Bending Strength ◽  
High Alumina ◽  
Alumina Ceramics ◽  
Large Area ◽  
Structural Applications ◽  
Worn Surfaces

The wear resistances of four standard-grade high-alumina ceramics were evaluated and related to their machining ability. Three of the material grades contained 96% of alumina and 4% of either calcium silicate, or magnesium silicate, or manganese titanate in the starting-powder composition. The nominal alumina content in the fourth material was 99.7%. The specimens were fabricated using a low-pressure injection-molding forming technique, followed by thermal de-binding and sintering. After sintering the four materials differ significantly in their grain size, bending strength and Vickers hardness. No direct relationship between the microstructural parameters and the mechanical properties was found, but there was a grain-size dependence of the surface finish after grinding under industrial conditions. The two silicate-containing ceramics exhibited considerably higher wear resistances than the two silicate-free ceramics, but no direct relationship between the abrasive wear rate during grinding and the cutting time was observed. The cutting ability represents a valuable material characteristic for industrial practice, but it should not be directly used for predicting the wear rate during grinding. Quantitative differences in the cutting time and abrasive wear rate were manifested in the different topographies of the worn surfaces. Cutting resulted in relatively large area fractions of plastically deformed surfaces, whereas pullouts dominated the worn surfaces after grinding.

Grain size effect on abrasive wear mechanisms in alumina ceramics

Wear ◽  
1993 ◽  
Vol 162-164 ◽  
pp. 258-268 ◽  
Author(s):  
Anoop K. Mukhopadhyay ◽  
Mai Yiu-Wing
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Grain Size Effect ◽  
Alumina Ceramics

scholarly journals Effect of WC Grain Size and Abrasive Type on the Wear Performance of HVOF-Sprayed WC-20Cr3C2-7Ni Coatings

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 660
Author(s):  
Qun Wang ◽  
Yingpeng Zhang ◽  
Xiang Ding ◽  
Shaoyi Wang ◽  
Chidambaram Seshadri Ramachandran
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Test ◽  
Binder Phase ◽  
Repeated Impact ◽  
Wear Performance ◽  
The Matrix ◽  
Three Body

In order to investigate the effect of WC grain size on coatings’ properties and abrasive wear performance, a few WC-20Cr3C2-7Ni coatings with three different WC grain sizes were deposited by the high-velocity oxy-fuel (HVOF) thermal spray process. The phase compositions, microstructures, and mechanical properties of the coatings were investigated. Furthermore, the two- and three-body abrasive wear performances of the three coatings were tested by using SiC and SiO2 abrasives, respectively. The results show that all the three coatings were composed of WC, Cr3C2, and the Ni binder as well as the (W,Cr)2C phase. The abrasive wear resistance of the WC-20Cr3C2-7Ni coating monotonously increased with increasing WC grain size when the SiC abrasive was used in the two- and three-body abrasive wear tests. However, the wear resistance trend was reversed when the SiO2 abrasive was used in the three-body abrasive wear test. The specific wear rate of the WC-20Cr3C2-7Ni coating exposed to the SiC abrasive under the two-body abrasive wear test was the largest. The wear resistance of the coatings was more significantly affected by the hardness of the abrasive particles than the size of carbides present within the coating. The high hardness of SiC can cut both the carbide and the binder phase of the WC-based cermet coatings, resulting in a high wear rate, whereas the low hardness of SiO2 cuts and/or scratches the binder initially, and then it dislodges the carbides from the matrix. The dislodged carbides which were subsequently pulled out from the matrix by the repeated impact of the SiO2 abrasives result in a milder wear rate.

Role of composition and microstructure in the abrasive wear of high-alumina ceramics

Wear ◽  
1999 ◽  
Vol 225-229 ◽  
pp. 1050-1058 ◽  
Author(s):  
C.P. Doğan ◽  
J.A. Hawk
Keyword(s):  
Abrasive Wear ◽  
High Alumina ◽  
Alumina Ceramics

scholarly journals Wear Resistance Mechanism of Alumina Ceramics Containing Gd2O3

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2054 ◽  
Author(s):  
Tingting Wu ◽  
Jianxiu Su ◽  
Yongfeng Li ◽  
Hongyuan Zhao ◽  
Yaqi Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Wear Rate ◽  
Grain Boundary ◽  
Grain Growth ◽  
Water Environment ◽  
Resistance Mechanism ◽  
Alumina Ceramics ◽  
Industry Standard ◽  
Chinese Industry

Excellent wear resistance of alumina ceramics is a desirable quality for many products. The purpose of this work was to improve the wear resistance of 99% alumina ceramics in an Al2O3–Gd2O3–SiO2–CaO–MgO (AGSCM) system. The content of Gd2O3 varied from 0.01% to 1%. A test of wear rate was performed in a ball milling apparatus in a water environment according to the Chinese industry standard. The compositions and microstructure of this material, as well as the effect of bulk density on wear rate, were studied. The effect of Gd2O3 on phases, grain growth mode, and grain boundary cohesion was investigated. It was found that Gd2O3 could refine grain size, form compressive stress of the grain boundary, and promote the crystallization of CaAl12O19. The wear rate of this material was as low as 0.00052‰ (the Chinese industry standard wear rate is ≤0.15‰). The mechanisms for wear resistance of AGSCM ceramics were also determined.

WEAR BEHAVIOR OF NANOSTRUCTURED HYPOEUTECTIC Fe–B ALLOY

2017 ◽  
Vol 24 (02) ◽  
pp. 1750023 ◽  
Author(s):  
LICAI FU ◽  
JUN YANG ◽  
LINGPING ZHOU ◽  
WEIMIN LIU
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Behavior ◽  
Oxide Films ◽  
Coarse Grained ◽  
Nano Scale ◽  
Worn Surface ◽  
Worn Surfaces

The wear behavior of nanostructured hypoeutectic Fe[Formula: see text]B[Formula: see text] alloy was investigated in comparison with coarse grained counterpart. The friction coefficient of the Fe[Formula: see text]B[Formula: see text] alloy changed slightly with grain size. While the wear rate decreased as the grain size decreased to nano scale. Both Fe2O3 and Fe2SiO4 oxides were found on the worn surfaces in the nanostructured Fe[Formula: see text]B[Formula: see text] alloy, but only a few oxide films were observed for the coarse grained counterpart. These results suggested that the nanostructured eutectic was conducive to forming oxide films on the worn surface of the Fe[Formula: see text]B[Formula: see text] alloy, and improved the wear resistance.

THE EFFECT OF ABRASIVE MASS MOISTURE CONTENT ON THE ABRASION-RESISTANT STEEL WEAR RATE

Tribologia ◽  
2019 ◽  
Vol 284 (2) ◽  
pp. 75-82
Author(s):  
Krzysztof Ligier ◽  
Magdalena Lemecha ◽  
Jerzy Napiórkowski
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Moisture Content ◽  
Abrasive Wear ◽  
Quartz Sand ◽  
Resistant Steel ◽  
Test Results ◽  
Moisture Contents

This paper presents the results of tests for Hardox Extreme Steel wear rate in an abrasive mass of varying moisture contents. The tests were conducted by the “rotating bowl” method using quartz sand with a grain size of 0.5–1.4 mm. The obtained test results show that an abrasive mass with a moisture content of 7% exhibits the lowest rate of steel abrasive wear. However, the highest wear rate was noted for an abrasive mass with a moisture content of 14%. A further increase in moisture content resulted in a decrease in the steel wear rate.

Low-Temperature-Tunnel of High-Alumina Ceramics with Good Wear Resistance

2014 ◽  
Vol 941-944 ◽  
pp. 538-541
Author(s):  
Jun Chang Liu ◽  
Bo Lin Wu
Keyword(s):  
Wear Resistance ◽  
Low Temperature ◽  
Wear Rate ◽  
Sintering Temperature ◽  
Raw Material ◽  
High Alumina ◽  
Alumina Ceramics ◽  
Conventional Sintering ◽  
Low Wear ◽  
Industrial Alumina

As for the liquid-phase sintered (LPS) Al2O3 based on the CaO-MgO-Al2O3-SiO2 (CMAS) system, we found a strange phenomenon. It is commonly acknowledged that, the sintering temperature should be high corresponding with the increase of the content of Al2O3 in a special system. However, when the content of Al2O3 is limited within 95-98wt%, the conclusion is opposite. It means that there is a low-temperature sintering-tunnel. What’s more, as wear resistant materials, the wear rate of alumina ceramics reduces with the increasing of the content of Al2O3 among 95-98wt%. In this paper, taking industrial alumina as raw material, we obtain low-wear-rate high-alumina ceramics by conventional sintering in CMAS system. We explain and analyze the condition from the perspective of crystalline phase and microstructure by XRD and FESEM. The results show that the 98 porcelain is of better wear resistance and indicate excellent prospect in the fabrication of lower wear rate of high-alumina ceramics.

The effect of abrasive grain size of sad in liquid on abrasive wear rate of metal surface

1999 ◽  
Vol 2 (2) ◽  
pp. 31A-42A
Author(s):  
Gailan Ismaeel Hassan ◽  
◽  
Shawnm Rashid Jalal ◽  
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Metal Surface ◽  
Abrasive Grain

Increasing in wear resistance of excavating machine elements

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Thermomechanical Treatment ◽  
Cold Work ◽  
Hadfield Steel ◽  
Outer Side ◽  
Viii And Ix ◽  
Machine Elements ◽  
The Impact

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.

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