HEAT TREATMENTS OF TANZANIA RUBY AS MONITORED BY ESR SPECTROSCOPY

2000 ◽  
Vol 14 (16) ◽  
pp. 1693-1700 ◽  
Author(s):  
P. WINOTAI ◽  
T. WICHAN ◽  
I. M. TANG ◽  
J. YAOKULBODE
Keyword(s):  
Heat Treatment ◽  
Heat Treating ◽  
Hexagonal Structure ◽  
Blue Color ◽  
Spin Resonance ◽  
Gas Atmosphere ◽  
Two Factors ◽  
Maximum Decrease ◽  
Electron Spin Resonance Spectrometer

The main purpose of heat treatment is to find the optimum condition to either enchance or reduce the color in order to increase value of ruby. It was found that by heating a slightly bluish Tanzania ruby in oxygen gas atmosphere could lead to a more perfect ruby. While X-ray diffractometer found the maximum decrease in c/a ratio of the hexagonal structure after the heat treatment at 1200°C, the number of Fe 2+ ions converted to Fe 3+ was detected by electron spin resonance spectrometer and found to increase with heating temperatures. These were clearly two factors that reduced blue color in the Tanzania ruby. The best heat treating temperature to enhance the quality of the ruby was at 1300°C.

OPTIMIZATION OF HEAT TREATMENTS OF AFRICAN GREEN SAPPHIRES

2001 ◽  
Vol 15 (20) ◽  
pp. 873-882 ◽  
Author(s):  
P. WINOTAI ◽  
S. SAISENG ◽  
T. SUDYOADSUK
Keyword(s):  
Emission Spectra ◽  
High Ratio ◽  
Hexagonal Structure ◽  
Blue Color ◽  
Green Color ◽  
X Ray ◽  
Bluish Green ◽  
Spin Resonance ◽  
Maximum Decrease ◽  
Golden Color

Under suitable heating conditions designed for a particular sapphire it is possible to change the color in order to increase its value. It was found that heating African green sapphires in an oxygen atmosphere could improve their quality and thus increase their prices. The color of green sapphires is due to the presence of trace amounts of Fe 3+, Ni 3+, Fe 2+ and Ti 4+ ions. It is known that Fe 3+ yields pale yellow and Ni 3+ a golden color while the charge transfer mechanism between Fe 2+ and Ti 4+ gives sapphire its blue color. It is obvious that the green color is due to a high ratio of Fe 2+ to Ti 4+. By using an X-ray diffractometer, the maximum decrease of the c/a ratio of the hexagonal structure is found to occur after heat treatment at 1200°C. These results are also confirmed by the shift of emission spectra toward shorter wavelengths. Furthermore, the number of Fe 2+ ions converted to Fe 3+ was detected by electron spin resonance spectrometry and found to increase with temperature. The sapphire with trace Ti 4+ ions, appeared slightly bluish green after heating at 1500°C. The optimal temperature is therefore at 1300°C, where we can achieve yellowish green sapphires instead.

OPTIMIZATION OF HEAT TREATMENTS OF VIETNAMESE RUBIES

2003 ◽  
Vol 17 (29n30) ◽  
pp. 1537-1546 ◽  
Author(s):  
P. WINOTAI ◽  
P. LIMSUWAN ◽  
S. RITTIKULSITTICHAI
Keyword(s):  
Heat Treatment ◽  
Electron Spin Resonance ◽  
Color Change ◽  
Hexagonal Structure ◽  
Heating Condition ◽  
Yellow Color ◽  
Spin Resonance ◽  
Electron Spin Resonance Spectrometer ◽  
Pale Yellow Color ◽  
Asymmetric Equilibrium

A suitable heating condition designed for a particular type of ruby is used to enhance the quality to increase its value. Heating Vietnamese rubies in an oxygen atmosphere may improve color and clarity, and thus increase their prices. The color of rubies is due to the presence of trace amounts of Cr 3+. Fe 3+ yields a pale yellow color and the charge transfer mechanism between Fe 2+ and Ti 4+ gives ruby an undesirable bluish color. Reducing this mechanism is possible by heating the ruby in oxygen so that most of the Fe 2+ is converted into Fe 3+ ions and thus they appear a more intense red. By using XRD we found that the c/a ratio of the hexagonal structure was smallest after heat treatment at 1300°C. The number of Fe 2+ ions converted to Fe 3+ was detected by an electron spin resonance spectrometer and found to increase with temperature. The ruby appeared a most intense red after heating at 1500°C for 12 hours. The color change is due to both the decrease in c/a ratio and the increase in the number of Fe 3+ ions. ESR experiments on ruby crystals by rotation about their c-axis show that Fe 3+ ions are a little off axis before heat treatment. After heat treatment at 1300°C they move to new asymmetric equilibrium positions towards larger O 2- triangles. It is not clear, however, if this Fe 3+ movement is related to the change in color. The asymmetry may arise due to some O2- vacancies.

PENGARUH KONSENTRASI RAGI Saccharomyces cerevisiae DAN LAMA FERMENTASI TERHADAP KUALITAS CUKA TOMI-TOMI (Flacourtia inermis)

2015 ◽  
Vol 4 (2) ◽  
pp. 50-55
Author(s):  
Sandra J Nendissa ◽  
Rachel Breemer ◽  
Nikholaus Melamas
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Experimental Design ◽  
Total Dissolved Solids ◽  
Total Sugar ◽  
Dissolved Solids ◽  
Randomized Experimental Design ◽  
Two Factors ◽  
Four Levels

This objectives of this research were both to study and determine the best level of concentration of yeast Saccharomyces cereviseae and period of fermentation on the quality of tomi-tomi vinegar (Flacourtia inermis). A completely randomized experimental design with two factors of treatment was applied in this research. The first factor was concentration of yeast S. cereviseae having four levels of tretament, i.e.: without the addition of yeast 0.5, 1 and 1.5 g yeast. The second factor was period fermentation with 1, 2, 3, 4, and 5 weeks. The result indicated that the concentration of yeast S. cereviseae 1.5 g and period fermentation 5 week produced a good tomi-tomi vinegar with total acids 51.22%, total dissolved solids 8.35, total sugar 8.07% and pH 5.40.

ALTEMP HX

Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.

CMW 100

Alloy Digest ◽  
2000 ◽  
Vol 49 (10) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Copper Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Age Hardening ◽  
High Tensile Strength ◽  
Electrical Components ◽  
Flash Welding ◽  
Hardening Heat Treatment

Abstract CMW 100 is a copper alloy that combines high tensile strength with high electrical and thermal conductivity. It responds to age-hardening heat treatment. It is used for flash welding dies, springs, electrical components, high-strength backing material for brazed assemblies, and wire guides. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-29. Producer or source: CMW Inc. Originally published as Mallory 100, August 1955, revised October 2000.

CONDULOY

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Beryllium Copper ◽  
Hardening Heat Treatment

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.

UNS A02960

Alloy Digest ◽  
1987 ◽  
Vol 36 (12) ◽  
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Heat Treating ◽  
Age Hardening ◽  
Casting Alloy ◽  
Passenger Cars ◽  
Temperature Performance ◽  
Mold Casting ◽  
Railway Passenger ◽  
Hardening Heat Treatment

Abstract UNS No. A02060 is an aluminum-mold casting alloy that responds to an age-hardening heat treatment. It is recommended for applications that require a combination of high tensile properties and good machinability. Among its many uses are fuel pump bodies, aircraft fittings and seat frames for railway passenger cars. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-285. Producer or source: Various aluminum companies.

ALMANITE W

Alloy Digest ◽  
1974 ◽  
Vol 23 (3) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Impact Strength ◽  
Surface Treatment ◽  
High Hardness ◽  
Heat Treating ◽  
Austenitic Matrix ◽  
Matrix Type ◽  
Martensitic Matrix ◽  
Cast Condition

Abstract ALMANITE W comprises a series of three types of austenitic-martensitic white irons characterized by high hardness and relatively good impact strength. Type W1 has a pearlitic matrix. Type W2 has a martensitic matrix, Type W4 is highly alloyed to provide an austenitic matrix in the as-cast condition which may be further modified to give a martensitic matrix by heat treatment or by refrigeration. This datasheet provides information on composition, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-42. Producer or source: Meehanite Metal Corporation.

INCO ALLOY 330

Alloy Digest ◽  
1992 ◽  
Vol 41 (5) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Treating ◽  
High Temperature Alloy ◽  
Nickel Iron ◽  
Temperature Performance ◽  
Inco Alloy ◽  
Iron Chromium

Abstract INCO ALLOY 330 is a nickel/iron/chromium austenitic alloy, not hardenable by heat treatment. It is a solid solution strengthened high-temperature alloy. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-403. Producer or source: Inco Alloys International Inc..

ALUMINUM C355.0

Alloy Digest ◽  
1983 ◽  
Vol 32 (2) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Treating ◽  
Age Hardening ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Parts ◽  
Hardening Heat Treatment

Abstract ALUMINUM C355.0 is a high-purity casting alloy that responds to an age-hardening heat treatment. It can be cast successfully by the sand and permanent-mold processes. Its castings characteristics are excellent and it is recommended for pressure-tight castings. It has good resistance to corrosion. Its applications include propeller gear boxes, crankcases and stressed structural parts in aircraft. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-243. Producer or source: Various aluminum companies.

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