Microstructural Characterization of Al2O3/Gamma Titanium Aluminide Composites

1992 ◽  
Vol 273 ◽  
Author(s):  
G. Das ◽  
S. Krishnamurthy
Keyword(s):  
Electron Microscopy ◽  
Titanium Aluminide ◽  
Hot Isostatic Pressing ◽  
Microstructural Characterization ◽  
Matrix Interface ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium ◽  
Matrix Microstructure ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

ABSTRACTAlumina (A12O3) fibers were incorporated into gamma titanium aluminide(TiAl) based powders by hot isostatic pressing (HIP'ing). The microstructure of as-HIP'd and heat treated composite specimens were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM studies reveal the presence of an amorphous reaction zone at the fiber/matrix interface. Numerous dislocations, dipoles and loops as well as twins are observed in A12O3 fibers. In addition, it is determined that the fiber/matrix interface stability is significantly affected by the matrix microstructure.

scholarly journals Advancement of Plasma Cold-Hearth Melting for Production of Gamma Titanium Aluminide Alloys within Arconic

2020 ◽  
Vol 321 ◽  
pp. 08008
Author(s):  
Ernie Crist ◽  
Birendra Jena ◽  
Michael Jacques ◽  
Matt Dahar ◽  
Don Li ◽  
...  
Keyword(s):  
Titanium Aluminide ◽  
Centrifugal Casting ◽  
Hot Isostatic Pressing ◽  
Industrial Applications ◽  
Vacuum Arc ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium ◽  
Arc Melting ◽  
The Impact ◽  
Titanium Aluminide Alloys

Utilization of gamma titanium aluminide alloys in aerospace and automotive/industrial applications has placed significant demand on melting sources for products to be used in cast, wrought, and direct-machining applications. There is also an increased demand for input stock used in gas atomization of powders. Current technologies used in ingot manufacturing include plasma arc melting, vacuum arc melting, and induction skull melting + centrifugal casting. Subsequent processing may include forging, re-melting + casting, or machining directly into components. Over the past six years, Arconic Engineered Structures has developed a robust melting method using plasma cold-hearth melting technology, including the design and implementation of a new 3-torch system to produce Ti-48-2-2 cast bars. General discussions concerning plasma cold-hearth melting, manufacturing challenges, and metallurgical attributes associated with cast Ti-48-2-2 bars will be reviewed. Emphasis will be on understanding the impact of hot isostatic pressing on internal voids, residual stress cracking and resulting mechanical properties.

scholarly journals Microstructural characterization of twin-roll cast gamma titanium aluminide sheets.

1991 ◽  
Vol 31 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Munetsugu Matsuo ◽  
Toshihiro Hanamura ◽  
Masao Kimura ◽  
Naoya Masahashi ◽  
Toshiaki Mizoguchi ◽  
...  
Keyword(s):  
Titanium Aluminide ◽  
Microstructural Characterization ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium ◽  
Twin Roll Cast ◽  
Twin Roll

The Effects of Hot Isostatic Pressing Conditions on the Microstructure of Beta-Gamma Titanium Aluminide Powder Alloys

2010 ◽  
Vol 89-91 ◽  
pp. 325-330
Author(s):  
D. Laurin ◽  
Dong Yi Seo ◽  
H. Saari ◽  
Young Won Kim
Keyword(s):  
Titanium Aluminide ◽  
Volume Fraction ◽  
Hot Isostatic Pressing ◽  
Beta Phase ◽  
Hot Workability ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium ◽  
Isostatic Pressing ◽  
Powder Alloys ◽  
Titanium Aluminide Alloys

The effects of hot isostatic pressing temperature and cooling rate on the microstructure of two powder metallurgy beta-gamma titanium aluminide alloys with nominal compositions TiAl 4Nb 3Mn (G1) and TiAl-2Nb-2Mo (G2) are investigated. Particular attention is placed on the volume fraction of the beta phase, which is known to improve the hot workability. The alloys are consolidated by hot isostatic pressing at 1200 °C, 1250 °C, and 1300 °C, and cooled at rates between 3.0 °C/min and 17.5 °C/min. The volume fraction of beta phase in both alloys was unaffected by the change in cooling rates. The volume fraction of the beta phase in G2 decreased linearly from ~9.5 vol.% to ~3.5 vol.% with increasing HIP temperature from 1200 °C to 1300 °C.

Limitations of an Indentation Model for Grinding Gamma Titanium Aluminide

2002 ◽  
Author(s):  
H. Ali Razavi ◽  
Steven Danyluk ◽  
Thomas R. Kurfess
Keyword(s):  
Force Control ◽  
Titanium Aluminide ◽  
Normal Force ◽  
Removal Rate ◽  
Cubic Boron Nitride ◽  
Normal Component ◽  
Grinding Force ◽  
Cutting Depth ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium

This paper explores the limitations of a previously reported indentation model that correlated the depth of plastic deformation and the normal component of the grinding force. The indentation model for grinding is studied using force control grinding of gamma titanium aluminide (TiAl-γ). Reciprocating surface grinding is carried out for a range of normal force 15–90 N, a cutting depth of 20–40 μm and removal rate of 1–9 mm3/sec using diamond, cubic boron nitride (CBN) and aluminum oxide (Al2O3) abrasives. The experimental data show that the indentation model for grinding is a valid approximation when the normal component of grinding force exceeds some value that is abrasive dependent.

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