Glass-Ceramic Protective Coating for Titanium Alloys

This study was aimed at producing a porous layered glass ceramic material with a decorative-protective coating via one-stage firing. Waste products were used as gas-forming agents to fabricate a glass ceramic material, which partially solves a problem of their utilization; available natural raw materials were also used as gas-forming agents. A decorative-protective coating was applied simultaneously with the formation of the main layers of the material. It consisted of glass cullet and various amounts of coloring oxide. Firing of the samples was carried out at the temperature of 7500С. The coating containing 99.9 wt.% of glass cullet and 0.1 wt.% of Cr2O3 with the thickness of 425 m and having a greenish color was stated to be the coating of the highest quality. As a result of the research, a three-layer porous glass ceramic material was obtained with a low coefficient of thermal conductivity (0.056 W m–1 K–1). The presence of a fourth front decorative-protective layer will allow using this material in construction as a heat-insulating and structural material without additional cladding.

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Glass–ceramic coatings on titanium alloys for high temperature oxidation protection: Oxidation kinetics and microstructure

Corrosion Science ◽

10.1016/j.corsci.2013.04.041 ◽

2013 ◽

Vol 74 ◽

pp. 178-186 ◽

Cited By ~ 42

Author(s):

Minghui Chen ◽

Wenbo Li ◽

Mingli Shen ◽

Shenglong Zhu ◽

Fuhui Wang

Keyword(s):

High Temperature ◽

Titanium Alloys ◽

Glass Ceramic ◽

Oxidation Kinetics ◽

High Temperature Oxidation ◽

Ceramic Coatings ◽

Temperature Oxidation ◽

Oxidation Protection ◽

Glass Ceramic Coatings

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Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064669 ◽

1971 ◽

Vol 29 ◽

pp. 122-123

Author(s):

N. E. Paton ◽

D. de Fontaine ◽

J. C. Williams

Keyword(s):

Electron Microscope ◽

Titanium Alloys ◽

Direct Observation ◽

Dark Field ◽

X Ray Diffraction ◽

Resistivity Measurements ◽

Selected Area Electron Diffraction ◽

Ti Alloys ◽

Thin Foils ◽

Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

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The Ordered Phase Formation in Ti-Al-Ga Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069193 ◽

1970 ◽

Vol 28 ◽

pp. 440-441

Author(s):

Shiro Fujishiro ◽

Harold L. Gegel

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Titanium Alloys ◽

Growth Kinetics ◽

Stoichiometric Composition ◽

Good Potential ◽

Alpha Titanium ◽

Cold Rolled ◽

Kinetics Of ◽

Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105758 ◽

1988 ◽

Vol 46 ◽

pp. 738-739

Author(s):

G. Das ◽

R. E. Omlor

Keyword(s):

Titanium Alloys ◽

Reaction Zone ◽

Carbon Layer ◽

Fiber Reinforced ◽

Reaction Products ◽

Sic Fibers ◽

Sic Fiber ◽

The Matrix ◽

Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

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