Preparation of Synthetic Quartz Aggregates under Pressure

1991 ◽  
Vol 251 ◽  
Author(s):  
F. C. Luan ◽  
M. S. Paterson

ABSTRACTIn 1965 Griggs and Blacic [1,2] proposed that there is a “hydrolytic weakening” process in quartz and silicates whereby the breaking of Si-O bonds, involved in the movement of dislocations, is facilitated by the presence of water. This proposal aimed to explain the observed dramatic weakening of quartz crystals when they are exposed to water in tests at high temperature, as well as the observed strong contrast in creep strength between dry natural quartz crystals and rapidly-grown synthetic quartz crystals containing traces of water. Such a “hydrolytic” process may also underlie the observed effects of water in accelerating other phenomena such as self-diffusion of oxygen in quartz, aluminium-silicon ordering in feldspars, slow crack propagation in silicates, and recrystallization in quartz. A review of this field is given in Reference 3.

1978 ◽  
Vol 33 (3) ◽  
pp. 290-293 ◽  
Author(s):  
Dipak Chakraborty ◽  
Gerhard Lehmann

AbstractThe fractional intensities of different infrared vibration bands due to hydrogen impurities have been studied in clear natural quartz, amethyst, citrine and synthetic quartz. Integral absorptions of the different bands were found to increase linearly with total hydrogen concentration. The differences in intensity ratios for some prominent bands are distinctive for the type of quartz in some cases. The ratios of isotropic to anisotropic absorption from hydrogen impurities were found to increase with total hydrogen concentration.


Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.


Alloy Digest ◽  
2020 ◽  
Vol 69 (12) ◽  

Abstract Wieland Duro TZM is a molybdenum-titanium-zirconium-carbon alloy produced from pressed-and-sintered billets. Compared to unalloyed molybdenum, it exhibits higher recrystallization temperature and enhanced high-temperature strength and creep strength. Wieland Duro TZM is typically used between 700 and 1400 °C (1290 and 2550 °F) in a non-oxidizing environment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as machining and powder metal forms. Filing Code: Mo-20. Producer or source: Wieland Duro GmbH.


Alloy Digest ◽  
1998 ◽  
Vol 47 (12) ◽  

Abstract MO-RE 40MA is a fully austenitic heat-resistant alloy for elevated temperature applications. The alloy is microalloyed for creep strength and oxidation resistance. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance. Filing Code: Ni-548. Producer or source: Duraloy Technologies Inc.


Alloy Digest ◽  
1966 ◽  
Vol 15 (11) ◽  

Abstract Ti-679 is a titanium high temperature alloy having an excellent combination of short-time strength, creep strength and stability to 900 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ti-48. Producer or source: Titanium Metals Corporation of America.


Alloy Digest ◽  
2001 ◽  
Vol 50 (8) ◽  

Abstract Ti-17 is an a-rich near-B alloy that is sometimes classified as an a-B alloy. Unlike other B or near-B alloys, Ti-17 offers good creep strength up to 430 C (800 F). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance. Filing Code: TI-117. Producer or source: RMI Company.


Alloy Digest ◽  
2020 ◽  
Vol 69 (8) ◽  

Abstract ATI 6-2-4-2 is a near-alpha, high strength, titanium alloy that exhibits a good combination of tensile strength, creep strength, toughness, and long-term stability at temperatures up to 425 °C (800 °F). Silicon up to 0.1% frequently is added to improve the creep resistance of the alloy. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ti-169. Producer or Source: ATI.


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