High-Temperature, Cobalt-Tungsten Alloys for Aerospace Applications

1965 ◽  
Vol 87 (1) ◽  
pp. 9-20 ◽  
Author(s):  
J. C. Freche ◽  
R. L. Ashbrook ◽  
G. D. Sandrock
Keyword(s):  
High Temperature ◽  
Rupture Strength ◽  
Rupture Life ◽  
High Stress ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Tungsten Alloys ◽  
Aerospace Applications ◽  
Temperature Capability ◽  
Nickel Base

The high-temperature capability and workability of cobalt-tungsten alloys for aerospace applications is discussed. The average life at 1850 F and 15,000 psi of the strongest previously reported alloy, Co-25 W-1Ti-1Zr-0.4C, was doubled from 92 to 185 hr by small additions of chromium and rhenium. At 2200 F and 5000 psi, the strongest alloy, Co-25W-1Ti-1Zr-3Cr-2Re-0.4C, had a rupture life of 23 hr; the elevated-temperature rupture strength compared favorably with the strongest available conventional (high-chromium) cobalt-base alloys. Above approximately 2035 F and at reasonably high stress levels (10,000 and 15,000 psi), its stress-rupture life also exceeded those of the strongest known nickel-base alloys, including the NASA tantalum-modified alloy and SM-200. It is particularly significant that even the strongest alloys of this series were readily hot-rolled. Ingots 1/2 in. thick were reduced to 0.065-in. sheet and subsequently cold-rolled to 0.0125-in. sheet. Elongations as high as 31 percent were obtained at room temperature with annealed sheet specimens. The good ductility obtained suggests that these alloys could be fabricated into complex shapes required for various aerospace and other applications. Although the strongest alloys had a chromium content of only 3 percent, they did not oxidize catastrophically in air.

ALLOY 713LC

Alloy Digest ◽  
1966 ◽  
Vol 15 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Rupture Strength ◽  
Base Alloy ◽  
High Stress ◽  
Stress Rupture ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract ALLOY 713LC is a nickel-base alloy possessing high stress-rupture strength up to 1700 F combined with excellent resistance to thermal fatigue. It is recommended for turbine wheels. 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: Ni-118. Producer or source: Austenal Microcast Division, Howmet Corporation.

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 176-177
Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Volume ◽  
Precipitate Morphology ◽  
Stress Rupture Life ◽  
Nickel Base ◽  
Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.

Influence of Heat Treatment on γ´ Phase and Property of a Directionally Solidified Superalloy

2018 ◽  
Vol 37 (3) ◽  
pp. 271-276
Author(s):  
P. C. Xia ◽  
K. Xie ◽  
H. Z. Cui ◽  
J. J. Yu
Keyword(s):  
Heat Treatment ◽  
Aging Temperature ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
Nickel Base Superalloy ◽  
Directionally Solidified ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Nickel Base

AbstractThe effects of heat treatment process on microstructure and properties of a nickel base superalloy are investigated. The size of γ´ phase decreases and the stress rupture life of alloy at 1100 °C/60 MPa drops with the rise of cooling rate. The hardness at room temperature also increases. The size of cuboidal γ´ precipitate and the volume of spherical γ´ precipitate increase with the rise of aging temperature. With higher aging temperature, the alloy exhibits bimodal γ´ phase. A reasonable combination of the size and volume fraction of cuboidal and spherical γ´ phase can obtain better stress rupture property at 1100 °C/60 MPa.

EFFECTS OF CRYSTAL ORIENTATION ON STRESS RUPTURE BEHAVIOR OF A Ni3Al-BASE SINGLE CRYSTAL SUPERALLOY IC6SX

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2952-2957
Author(s):  
LIWU JIANG ◽  
SHUSUO LI ◽  
MEILING WU ◽  
YAFANG HAN
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Crystal Orientation ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Area Reduction ◽  
Crystal Orientations ◽  
Rupture Behavior

The effect of the crystal orientation on the stress rupture behavior of the Ni 3 Al -base Single Crystal alloy IC6SX under the test condition of 1100°C/120Mpa has been studied. The results showed that the stress rupture lives of the specimens with [001], [011] and [111] crystal orientations were 205.45h, 268.6h and 485h, respectively, i.e., the specimen with [111] crystal orientation had the longest stress rupture life. The results of the tests also showed the significant different of high temperature stress rupture elongation and area reduction for different crystal orientation specimens, i.e., the ruptured elongations for the specimens with [001], [011] and [111] crystal orientations were 61.9%, 22.9% and 28.8%, and the values of area reduction for the specimens with [001], [011]and [111] crystal orientations were 11.7%, 12.2%and 7.3% respectively.

Mechanical Behavior of As-Cast and High Temperature Exposed Ni-Base Superalloy B1900

2004 ◽  
Vol 449-452 ◽  
pp. 541-544 ◽  
Author(s):  
I.S. Kim ◽  
Baig Gyu Choi ◽  
Seong Moon Seo ◽  
Chang Yong Jo
Keyword(s):  
High Temperature ◽  
Tensile Deformation ◽  
Rupture Life ◽  
Stress Rupture ◽  
Thermal Exposure ◽  
Tensile Specimen ◽  
Dislocation Network ◽  
Stress Rupture Life ◽  
Cast Specimen ◽  
Base Superalloy

Microstructural evolution during high temperature exposure and its effects on tensile and stress rupture properties of the Ni-base superalloy B1900 have been studied. Tensile deformation of the as-cast specimen was concentrated in the localized slip bands in general. Stacking faults and deformation twins were observed in the as-cast tensile specimen tested at 871°C where the alloy exhibited the lowest ductility. Dense dislocation network formed at γ/γ´ interface during thermal exposure caused homogenous deformation in the thermally exposed tensile specimen. Thermal exposure did not have significant effect on the stress rupture lives of the alloy at 760°C and at and above 871°C but it reduced stress rupture life of the alloy at 816°C γ´ coarsening and coherency loss at the γ/γ´ interface during thermal exposure were primarily responsible for the deterioration of mechanical properties and characteristic deformation behavior of the alloy.

CENTRALLOY 4848

Alloy Digest ◽  
1995 ◽  
Vol 44 (8) ◽  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Rupture Strength ◽  
High Stress ◽  
Stress Rupture ◽  
Good Resistance ◽  
Temperature Performance ◽  
Resistance To Oxidation

Abstract CENTRALLOY 4848 (HK-40) is a cast austenitic 25% chromium-20% nickel-stainless steel. A balanced composition provides excellent structural stability, high stress rupture strength and good resistance to oxidation and carburization. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: SS-604. Producer or source: Centracero S.A.

The Role of Solidification Rate on Fiber Distribution and Mechanical Properties of a Directionally Solidified Nickel Base-Tac Eutectic

1981 ◽  
Vol 12 ◽  
Author(s):  
John L. Walter
Keyword(s):  
Base Alloy ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Strength ◽  
Directionally Solidified ◽  
Fiber Density ◽  
Alloy Matrix ◽  
Stress Rupture Life ◽  
Nickel Base

ABSTRACTA nickel base-TaC eutectic alloy consisting of 53 wt % Ni, 11 W, 3 Re, 5 Co, 3 Mo, 2 Al, 21.67 Ta and 1.33 C was directionally solidified at rates from 0.32 to 3.8 cm/hr. Samples were taken from the regions of aligned TaC fibers and tested in tension at 1000°C and in stress-rupture. The fiber density increased from 1×106 fibers/cm2 at 0.32 cm/hr to 27×106 fibers/cm2 at 3.8 cm/hr. The stress-rupture life at 927°C and 275.6 MPa ranged from 4 hrs for samples solidified at 0.32 cm/hr to 4187 hrs for the sample solidified at 2.54 cm/hr at which time the test was terminated. Examination, by transmission electron microscopy, of the samples tested at 1000°C in tension, to just the beginning of fiber breakage, revealed a change in the mode of deformation of the nickel-base alloy matrix with increasing fiber density. It was also seen that the TaC fibers deformed by two mechanisms; by slip and by the formation of stacking faults.It appears that tailoring the alloy composition to allow for higher solidification rates may be a more effective strengthener than alloying the matrix for high strength.

Sign in / Sign up

Export Citation Format

Share Document