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.

Preparation and Characterization of Al2O3 High Density Ceramic Materials

2013 ◽  
Vol 457-458 ◽  
pp. 266-269
Author(s):  
Chun Yan Jia ◽  
Dong Hong Li ◽  
Yong He Liu
Keyword(s):  
Sintering Temperature ◽  
Ceramic Materials ◽  
Volume Density ◽  
Raw Material ◽  
High Alumina ◽  
Molding Pressure ◽  
Alumina Powder ◽  
Alumina Ceramics ◽  
Shrinkage Ratio ◽  
Isostatic Compaction

With sub-micron alumina powder as raw material, high alumina ceramics were prepared through isostatic compaction. The volume density and shrinkage ratio were investigated. The influence of sintering temperature and molding pressure were studied on volume density and shrinkage ratio of ceramic. The results indicated that sintering characteristic of alumina ceramics could be improved at the appropriate sintering temperature and molding pressure and its sintering temperature could be decreased by using sub-micron alumina powder as raw material. 95 ceramics were prepared using sub-micron alumina as raw material, when the sintering temperature was 1550°C, molding pressure was 12 t, and ceramic volume density could be achieved 3.71g /cm3.

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.

Fabrication and Sinter-Ability of Ce3+-Doped YAG Ceramics by Low-Temperature Combustion Method

2011 ◽  
Vol 299-300 ◽  
pp. 493-497
Author(s):  
Zhi Qiang Wang ◽  
Xin Sun ◽  
Xiao Li Zhou
Keyword(s):  
Low Temperature ◽  
Sintering Temperature ◽  
Combustion Method ◽  
Linear Shrinkage ◽  
Raw Material ◽  
Low Temperature Combustion ◽  
Photoluminescence Properties ◽  
X Ray ◽  
Sintering Additive ◽  
Temperature Combustion

The phosphors YAG doped with Ce3+was prepared by low-temperature combustion method. Utilizing the prepared YAG powders as raw material and Li2O-CaO-ZnO-Y2O3-Al2O3-SiO2glass powder as sintering additive, YAG:Ce3+ceramics were sintered at 1400-1550°C for 10h in vacuum. Thesinter-ability of the YAG ceramics was studied by measuring the linear shrinkage rate. The phase, microstructure and photoluminescence properties of the YAG: Ce3+powders and ceramics were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) analysis. The results show that the sinter-ability properties of YAG:Ce3+ceramics was mainly associated with sintering temperature and contents of glass sintering additive; the best result was achieved when the sample was sintered at 1500°C and doped sintering additive of 1%.

Effects of Adding Form of Additives on the Structure and Properties of High-Purity Alumina Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1130-1132
Author(s):  
Qiang Ren ◽  
Xiu Lan Wu ◽  
Xuan Meng He
Keyword(s):  
High Purity ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Normal Pressure ◽  
The Body ◽  
Raw Material ◽  
Sintering Process ◽  
Alumina Ceramics ◽  
Dry Pressing ◽  
Α Al2o3

High-purity alumina ceramics was prepared using high-purity α-Al2O3 powder as raw material, nitrates or oxides of magnesium, chromium and copper as additives by a wet ball milling with a later dry pressing forming and normal pressure sintering process. The influence of additives on the sintering temperature, microstructure and bending strength of the prepared alumina ceramics was studies. The results showed that the additive doped with nitrate can be dispersed uniformly in the body with molecule scale, and the oxides obtained by decomposing of nitrates have the higher reactivity. Thus, the nitrate additives have better capacity than oxide additives in reducing the sintering temperature and inhibiting the abnormal grain growth, and the alumina ceramics prepared by adding of nitrate additives have higher density and bending strength.

Deep Cryogenic Treatment and CrN Coating Effects on Micro-Scale Abrasion of Aluminum Alloy AA 6101-T4

2014 ◽  
Vol 936 ◽  
pp. 1047-1055 ◽  
Author(s):  
Edgar S. Ashiuchi ◽  
Volker F. Steier ◽  
Cosme R.M. Silva ◽  
Tales D. Barbosa ◽  
Tiago F.O. Melo ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Wear Rate ◽  
Cryogenic Treatment ◽  
Deep Cryogenic Treatment ◽  
Low Wear ◽  
The Impact ◽  
Improve Wear Resistance ◽  
Wear Tests

The endurance of components made of aluminum and aluminum alloys is often limited by their low yield strength and by their low wear resistance. The aim of this paper is to investigate the effect of different methods that can improve wear resistance of aluminum alloys. As a first approach, a highly wear resistant chromium nitrite layer was deposited by plasma vapor deposition on the surface of the aluminum alloy AA 6101-T4. In the second method, an ultra-deep cryogenic treatment was selected. Both methods have been previously used to improve the wear resistance of other harder substrate materials, like tool steel. To investigate the impact of the two methods on the wear resistance of such alloy, micro abrasive wear tests were carried out and an analysis based on the Archard’s law was considered. The results showed a decrease of the wear rate by 29% and 26% for the coated and for the cryogenically treated specimens, respectively, when compared to the as received material. The work also investigated the performance of three different methods (Allsopp, Double Intercept and Polynomial AT) usually considered to calculate the wear rate of coated samples. The three methods presented similar measures of wear rate for the substrate and for the coating

scholarly journals Pengaruh pack carburizing media arang tempurung kelapa terhadap ketahanan aus baja komersial dengan variasi pelumas.pdf

2018 ◽  
Vol 13 (1) ◽  
pp. 16
Author(s):  
Wahyu Richard Nugraha ◽  
Muhammad Iqbal ◽  
Sri Chandrabakty
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Raw Material ◽  
Coconut Shell ◽  
Water Medium ◽  
Wear Factor ◽  
Carburizing Process ◽  
Test Result

This research was conducted to determine the effect of carburizing pack of charcoal shell on commercial wear resistance of steel with variation of lubricant. Carbon used is coconut shell charcoal. Carburizing pack process is done at temperature 950oC with quenching water medium and tempering with temperature 200oC, after carburizing pack process then do wear wear with variation of SAE 40 oil, SAE 90, SAE 140 and also without lubricant (TP). The wear rate on specimens undergoing carburizing process for SAE 40 and SAE 90 testing was 0.08% with wear factor of 0.00193 mm3 / N.km and 0.00202 mm3 / N.km, then for SAE 140 test the wear rate 0.05% and wear factor of 0.00128 mm3 / N.km, as well as for non-lubricant testing (TP) of 0.31% and wear factor of 0.00807 mm3 / N.km. While testing of raw material at SAE test 40 wear rate and wear factor 0,19% and 0,00504 mm3 / N.km, for SAE 90 test result 0,21% and 0,00541 mm3 / N.km, and result Wear rate of SAE 140 test equal to 0,0,18% with wear factor 0,00459 mm3 / N.km then testing without lubricant (TP) equal to 3,59% with wear factor equal to 0,09537 mm3 / N.km.

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.

Effect of Yb2O3 and Tm2O3 on the wear resistance of high-alumina ceramics

Wear ◽  
2020 ◽  
Vol 452-453 ◽  
pp. 203281 ◽  
Author(s):  
Tingting Wu ◽  
Yongfeng Li ◽  
Guanjun Liu ◽  
Hongyuan Zhao ◽  
Bolin Wu
Keyword(s):  
Wear Resistance ◽  
High Alumina ◽  
Alumina Ceramics

Preparation of the System of MgO-CaO-SiO2-Al2O3-Y2O3 Wear-Resistant Alumina Ceramics

2014 ◽  
Vol 941-944 ◽  
pp. 542-546 ◽  
Author(s):  
Yuan Xiong ◽  
Bo Lin Wu
Keyword(s):  
Wear Rate ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Alumina Ceramic ◽  
Pressureless Sintering ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
Wear Resistant ◽  
X Ray ◽  
Ceramic Samples

In order to improve the wear resistance and reduce the sintering temperature of alumina ceramics, Y2O3powder added in the system of MgO-CaO-SiO2-Al2O3alumina ceramics were prepared by the technique of pressureless sintering. The properties of the ceramic samples were investigated by the measurements of bulk density, wear rate, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the wear rate of alumina ceramic contenting Y2O3 of the 0.8wt% is 0.041‰. Adding the yttrium oxide to the raw materials and then calcine them to ceramics, which can reduces the sintering temperature, promote the densification and improve wear-resistant property of alumina ceramics.

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