scholarly journals Ageing of Zirconia Dedicated to Dental Prostheses for Bruxers Part 2: Influence of Heat Treatment for Surface Morphology, Phase Composition and Mechanical Properties

2019 ◽  
Vol 58 (1) ◽  
pp. 218-225
Author(s):  
Damian S. Nakonieczny ◽  
Agata Sambok ◽  
Magdalena Antonowicz ◽  
Marcin Basiaga ◽  
Zbigniew K. Paszenda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
High Temperature ◽  
Surface Morphology ◽  
Aging Process ◽  
Negative Impact ◽  
Bending Test ◽  
High Temperature Heat Treatment ◽  
Dental Prostheses

Abstract Purpose: This part of the study focuses on the influence of zirconia heat treatment for surface morphology, phase composition and mechanical properties Methods: Zirconia samples was prepared with ISO 13356:2013 and ISO 14704:2008 recommendations. X-ray diffraction, observations (SEM) and (AFM), microhardness (Olivera & Phara method), and static bending test (4PBT) were taken. Results: characterization of YSZ and high temperature heat treatment has clearly shown that the aging process influences the change in phase composition of the material, significantly worsening the topography. In turn, re-treatment of the high temperature made after the artificial aging process results in reverse transformation of the desired tetragonal phase, but does not affect the improvement of surface morphology. Conclusions: The research made it possible to assess the negative impact of the zirconium oxide aging simulation process. Because of the failure to achieve the intended results, it was also proved that the high-temperature re-processing was not appropriate.

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

Effect of High-Temperature Heat Treatment on Mechanical Property of Cr-Geopolymer Composite

2011 ◽  
Vol 399-401 ◽  
pp. 469-473
Author(s):  
Mei Rong Wang ◽  
Yi Zheng ◽  
De Chang Jia ◽  
Yu Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Property ◽  
Treatment Temperature ◽  
Bending Test ◽  
Chromium Powder ◽  
Three Point Bending ◽  
High Temperature Heat Treatment ◽  
Micro Cracks ◽  
Before And After

Chromium powder reinforced geopolymer composite (Cr/geopolymer) was prepared in order to enhance its thermal conductivity and mechanical properties. The phase composition, microstructure and mechanical properties of Cr/geopolymer before and after heat treatment at 900, 1000, 1100 and 1200°C were investigated by the X–ray diffraction (XRD), scanning electron microscopy (SEM) and three–point bending test. With increasing heat treatment temperature from 900 to 1100°C, mechanical property of Cr/geopolymer increased gradually and at 1100°C flexural strength got the peak value, which was 325% higher than that of specimens without heat treatment. Cr/geopolymer treated at 900°C did not completely transform into crystalline phase, and many micro cracks around the chromium particles were observed. Cr/geopolymer treated at 1000–1100°C completely crystallized into leucite phase, and the metal chromium remained its original state. Meanwhile, most of the micro cracks were closed. When the temperature further increased to 1200°C, many visible defects were observed in Cr/geopolymer, and chromium oxide appeared in the interface of Cr/geopolymer, which had detrimental effect on the heat conduction and mechanical property of the composite.

Study on the Heat–Treatment Reinforcement of Aluminum Nitride–Silicon Carbide Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Li Ningfang ◽  
Zhang Hongquan ◽  
Wang Guomei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Silicon Carbide ◽  
Phase Composition ◽  
High Temperature ◽  
Grain Boundary ◽  
Aluminum Nitride ◽  
Phase Structure ◽  
Glass Phase ◽  
Boundary Phase

AbstractThe effects of heat – treatment on the mechanical properties of AIN – SiC whisker composites with Y2O3 and SiO2 additives has been studied. When the sample containing 10 wt% Y2O3 +SiO2 (Y2O3/SiO2= 1/0. 66) was treated at 1300°C in air for 140 hours the strength of compositqs was raised from 481 MPa to 784 MPa.The phase composition, microstructure and grain boundary phase structure have been characterized by combining XRD, SEM, TEM/EDXA and HREM techniques. The reinforcement mechanism of the composites results from crystallization of the glass phase in the grain boundary at the high temperature oxidizing atmosphere to form the crossing structure of 2Hδ Sialon fibrous phase and SiC whisker.

ALUMINUM 319.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Rear Axle ◽  
Heat Treating ◽  
General Purpose ◽  
Temperature Performance

Abstract ALUMINUM 319.0 is a general-purpose foundry alloy that is moderately responsive to heat treatment. It has excellent casting characteristics and good mechanical properties. Among its many uses are crankcases, housings, engine parts, typewriter frames and rear-axle housings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as creep and fatigue. It also includes information on low and high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-256. Producer or source: Various aluminum companies.

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