Effect of Li2O, K2O and ZnO on Vitrified Bond Composites for CBN Grinding Wheels

2016 ◽  
Vol 874 ◽  
pp. 193-198 ◽  
Author(s):  
Zi Xuan Wang ◽  
Tian Biao Yu ◽  
Ji Zhao ◽  
Xue Zhi Wang ◽  
Xue Sun ◽  
...  
Keyword(s):  
Mechanical Property ◽  
High Temperature ◽  
Bending Strength ◽  
Gas Bubbles ◽  
Microstructure Analysis ◽  
Depth Of Field ◽  
Grinding Wheels ◽  
Three Point Bending ◽  
Vitrified Bond

To investigate the effect of Li2O, K2O and ZnO on SiO2-Al2O3-B2O3-Na2O vitrified bond for CBN grinding wheels, the refractoriness and fluidity of specimens with different additions were studied. The bending strength was measured by three-point bending tester and the microstructures were observed by super Depth-of-Field microscope. The results show that Li2O, K2O and ZnO can reduce the refractoriness and increase the high-temperature fluidity. Li2O and K2O make a contribution to improving the bending strength; however ZnO is harmful to specimens’ mechanical property. Additionally, the fluidity is important to control the number of gas bubbles in specimen according to the microstructure analysis.

Joining of SiC Ceramic to Graphite Using Ni-51Cr Powders as Filler

2008 ◽  
Vol 368-372 ◽  
pp. 1600-1602 ◽  
Author(s):  
Yang Wu Mao ◽  
Shu Jie Li ◽  
Lian Sheng Yan
Keyword(s):  
High Temperature ◽  
Chemical Reactions ◽  
Reaction Layer ◽  
Bending Strength ◽  
Weld Zone ◽  
High Strength ◽  
Interfacial Area ◽  
Three Point Bending ◽  
Sic Ceramic ◽  
Points Of View

Joining of SiC ceramic to graphite is important from both technical and economical points of view. High temperature brazing of recrystallized SiC ceramic to high strength graphite has been realized using Ni-51Cr (consisting of Ni + 51wt% Cr powders) powders as filler. The obtained maximum three-point bending strength of joints is 32.3MPa, which is equal to 80.8% of the strength of the graphite. Microstructure and phase analysis reveals that interdiffusions and chemical reactions take place in the weld zone. A reaction layer and an interlayer form in the interfacial area. The reaction layer, of which the thickness is about 60-100μm, is contacted with the SiC ceramic. The interlayer with the thickness of about 200μm exists between the graphite and the reaction layer. The reaction layer is mainly composed of Ni2Si, while the interlayer is mainly composed of Cr23C6 and Ni2Si.

Bending Behavior of Glass Fiber Grid Reinforced Gussasphalt

2015 ◽  
Vol 744-746 ◽  
pp. 754-757
Author(s):  
Bo Gao ◽  
Min Wang ◽  
Zeng Heng Hao
Keyword(s):  
Composite Material ◽  
High Temperature ◽  
Glass Fiber ◽  
Bending Strength ◽  
Bending Test ◽  
Material Technology ◽  
Bending Performance ◽  
Three Point Bending ◽  
Bending Strain ◽  
Bending Behavior

In combination with the composite material technology, add the glass fiber grid into gussasphalt deck pavement system to form glass fiber grid reinforced gussasphalt. Analysis shows that adding the grid can increase the bending performance. Three point bending test was did to do verification and results were indicate that glass fiber grid can improve the anti-bending strength and anti-bending strain in high temperature.

Study of High Temperature Performance and Low Temperature Property on Layered Silicate Modified Asphalt Concrete

2012 ◽  
Vol 509 ◽  
pp. 189-193 ◽  
Author(s):  
Shao Peng Wu ◽  
Tian Gui Liu ◽  
Ling Pang ◽  
Ting Wei Cao ◽  
Pan Pan
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Concrete ◽  
Bending Strength ◽  
Layered Silicate ◽  
Temperature Property ◽  
Three Point Bending ◽  
Modified Asphalt ◽  
Temperature Performance ◽  
Low Temperature Property

Montmorillonite (MMT), a typical layered silicate, has been widely used to prepare modified asphalt. This paper investigates the high temperature performance and low temperature property on layered silicate modified asphalt concrete. The control concrete is prepared by base asphalt. Meanwhile, three-point bending, conventional and SHRP rutting tests are used to compare the properties of the two types of asphalt concrete. The results of conventional and SHRP rutting tests show that the modified asphalt concrete exhibits a better high temperature performance than the control concrete. And the maximum bending strength of modified asphalt concrete is higher than that of control concrete at the same temperature. It can be concluded that both the high temperature performance and low temperature property of asphalt concrete has been improved efficiently by utilization of layered silicate modified asphalt.

Oxidation Resistance and Bending Strength at High Temperatures of Ni/(ZrO2+Al2O3) Hybrid Materials

2018 ◽  
Vol 922 ◽  
pp. 104-109
Author(s):  
Hai Vu Pham ◽  
Makoto Nanko ◽  
Wataru Nakao
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Cross Section ◽  
High Temperatures ◽  
Room Temperature ◽  
Bending Strength ◽  
Bending Tests ◽  
Three Point Bending ◽  
Order Of Magnitude ◽  
Zone Development

Oxidation resistance and bending strength at high temperatures of 5 vol% Ni/(10 vol% ZrO2+Al2O3) were investigated in this paper. Oxidation tests were conducted at temperature ranging from 1100 to 1300oC for 1 to 24 h in air. The oxidation resistance of the composites was studied via observation of oxidized-zone development from a cross-section view after oxidation. Three-point bending tests were conducted at temperatures ranging from room temperature to 1200oC in order to estimate its performance at high temperatures. Bending strength of the composites achieved 1200 MPa at room temperature and 460 MPa at 1200oC. Dispersion of ZrO2in Ni/Al2O3composites enhanced both their room and high temperature bending strength. Nevertheless, ZrO2slightly degraded the oxidation resistance of the composites. The oxidation rate of Ni/(ZrO2+Al2O3) was one order of magnitude higher than that of Ni/Al2O3.

Preparation of Microcrystalline CBN Abrasive

2008 ◽  
Vol 368-372 ◽  
pp. 933-935 ◽  
Author(s):  
Ai Ju Zhang ◽  
Zhi Hong Li ◽  
Zi Cheng Li ◽  
Yu Mei Zhu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Three Point Bending ◽  
Microstructure Characteristics ◽  
Vitrified Bond ◽  
Sintering Method ◽  
Addition Amount

In this paper microcrystalline CBN abrasives are prepared with CBN powders and vitrified bond additives by pressureless sintering method. Mechanical properties of the products are measured by using single particle compressive strength tester and three-point bending strength tester. The effects of vitrified bond additives, the CBN powders particle size and the sintering temperature on the performance of microcrystalline CBN abrasives are investigated. The microstructure characteristics of microcrystalline CBN abrasives are examined. The results showed that the performance and microstructure of microcrystalline CBN abrasives are significantly influenced by particle size of CBN powder and the addition amount of vitrified bond.

Preparation of High Wear-Resistant Ceramic Parts

2011 ◽  
Vol 675-677 ◽  
pp. 163-166
Author(s):  
Ai Ju Zhang ◽  
Zi Cheng Li ◽  
Zhi Hong Li ◽  
Yu Mei Zhu
Keyword(s):  
Mechanical Property ◽  
Wear Resistance ◽  
Bonding Strength ◽  
Experimental Results ◽  
Wear Resistant ◽  
Three Point Bending ◽  
Abrasive Grains ◽  
Vitrified Bond ◽  
Electronic Microscope ◽  
Resistant Ceramic

Preparation of high wear-resistant ceramic parts was studied in this paper. The mechanical property was measured by the three-point bending tester, and the microstructures were analyzed with the scanning electronic microscope (SEM). The experimental results showed that vitrified bond CM2 was suitable for the preparation of high wear-resistant ceramic parts because of its lower refractoriness, and higher bonding strength sintering at 850oC. Moreover, containing 8- 12μm CBN abrasive grains, the ceramic parts reached higher strength and higher wear resistance than other samples.

Effects of hostile solutions on the static and dynamic behavior of carbon/epoxy composites

2021 ◽  
pp. 002199832110200
Author(s):  
H Ersen Balcıoğlu ◽  
Raif Sakin ◽  
Halit Gün
Keyword(s):  
Bending Strength ◽  
Laminated Composites ◽  
Fatigue Behavior ◽  
Laminated Composite ◽  
Test Sample ◽  
Solution Concentration ◽  
Static Stability ◽  
Three Point Bending ◽  
Sem Image ◽  
Solution Type

Fiber-reinforced laminated composite is often used in harsh environments that may affect their static stability and long-term durability as well as residual strength. In this study, the effect of heavy chemical environments such as acid and alkaline and retaining time for these environments on flexural strength and flexural fatigue behavior of carbon/epoxy laminated composites were investigated. In this context, carbon/epoxy was retained into an acidic and alkaline solution having 5%, 15%, and 25% concentration by weight for 1–4 months. Fatigue behavior of carbon/epoxy was determined under dynamic flexural load, which corresponds to 80%, 70%, 60%, 50%, and 40% of static three-point bending strength of the test sample. SEM image of damaged specimens was taken to describe the failure mechanism of damage which occurs after fatigue. Also, to better understand environmental condition on the fatigue life, results were compared with results of carbon/epoxy laminated composites, which were not retained into any environments (unretained). The test results showed that the solution type, solution concentration, and retaining time caused noticeable changes in the static and dynamic strengths of carbon/epoxy laminated composites.

scholarly journals Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec
Keyword(s):  
Flame Retardants ◽  
Elevated Temperatures ◽  
Bending Strength ◽  
Reaction System ◽  
Fire Retardant ◽  
Polyurethane Foams ◽  
Polymerization Reaction ◽  
Three Point Bending ◽  
One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

High-Temperature Brazing Molybdenum

2012 ◽  
Vol 586 ◽  
pp. 69-73
Author(s):  
Chia Chen Lin ◽  
Cheng Han Lee ◽  
Ren Kae Shiue ◽  
Hsiou Jeng Shy
Keyword(s):  
High Temperature ◽  
Intermetallic Phase ◽  
High Temperature Application ◽  
Three Point Bending ◽  
Brazed Joints ◽  
Temperature Application ◽  
Titanium Foils

High-temperature brazing molybdenum using palladium and titanium foils have been investigated in the experiment. Successful brazed joints are achieved from using the palladium filler foil. Brazed joints are fully dense and free of any intermetallic phase. Three point bending strengths of 246 and 233 MPa are obtained from joints using 100 m thick palladium filler foil brazed at 1580 and 1610 oC for 600 s, respectively. The application of palladium filler foil shows potential in brazing molybdenum for high-temperature application.

High Temperature Storage and Gamma Radiation Effects on Mechanical Properties of Stacked Die Package

2014 ◽  
Vol 895 ◽  
pp. 567-570
Author(s):  
Azman Jalar ◽  
Wan Yusmawati Wan Yusoff ◽  
Norinsan Kamil Othman ◽  
Irman Abdul Rahman
Keyword(s):  
High Temperature ◽  
Gamma Radiation ◽  
Radiation Effects ◽  
Storage Period ◽  
Bending Test ◽  
Three Point Bending ◽  
Micromechanical Properties ◽  
3D Ct Scan ◽  
High Temperature Storage ◽  
Temperature Storage

Effect of gamma radiation (1.33 MeV) and high temperature storage of semiconductor package towards micromechanical properties has been investigated. The in-house fabricated Quad Flat No Lead was exposed to gamma radiation with the dose of 5 Gy. Afterwards, high temperature storage was performed at 150 °C for 10, 100 and 1000 hours. Subsequently, the three point bending technique was carried out to obtain the micromechanical properties of semiconductor package. The fracture of the packages caused by three point bending test was subjected to 3D CT scan to capture the image of the fracture. Irradiated package shows the decreasing in their strength with increasing doses of gamma radiation. However, the strength of the package was improved after high temperature storage for 10 hours and decreased as the storage period is extended. Further analysis exhibited that high temperature storage for 10 hours is reveal as good thermal treatment for package in radioactive environment application.

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