In situ Transmission Electron Microscopy Tensile Tests of a Peak- to Overaged γ′-strengthened Nickel Base Alloy

2005 ◽  
Vol 20 (7) ◽  
pp. 1722-1727 ◽  
Author(s):  
Dietmar Baither ◽  
Volker Mohles ◽  
Eckhard Nembach

The commercial nickel base alloy NIMONIC PE16 is strengthened by nano-scale spherical coherent precipitates of the intermetallic γ′-phase Ni3(Al,Ti). A bulk polycrystalline specimen of NIMONIC PE16 was aged such that it was in the transition range from the peak- to the overaged state. This transition limits the duration of technically useful aging treatments of structural particle strengthened materials. Thin foils prepared from this specimen were stretched inside a transmission electron microscope, and the dislocation processes were observed under full load. Two dislocations with identical Burgers vectors of the type 1/2〈110〉 form a pair and glide together. The leading 1/2〈110〉 dislocation bypasses the γ′-precipitates and the trailing one shears them. These dislocation processes are also discussed with reference to the results of computer simulations.

1971 ◽  
Vol 93 (2) ◽  
pp. 225-230 ◽  
Author(s):  
M. Prager ◽  
G. Sines

A study was made of the embrittling effects of oxygen on Rene´ 41, a nickel-base alloy hardened by precipitation of gamma prime. In short time tensile tests in air it was found that from 750 to 900 deg C oxygen promoted initiation and rapid propagation of intergranular cracks, while in the absence of oxygen, tensile fractures were transgranular and ductility was much improved. Sensitivity to embrittlement by oxygen decreases with coarsening of gamma prime. When gamma prime is hyperfine, probably less than 100 Å, embrittlement is greatest and follows the predictions of a Petch-Stroh model for the initiation of cracks ahead of pile-ups of dislocations. In accordance with the model, the ductility of Rene´ 41 increased in proportion of the reciprocal of the square roo of grain size. Calculated on the basis of the model, the surface energy of Rene´ 41 in air was 400 ergs/cm2, considerably lower than would be expected for an alloy of nickel in an inert atmosphere.


Author(s):  
L. S. Lin ◽  
C. C. Law

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).


Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  

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.


Alloy Digest ◽  
1993 ◽  
Vol 42 (7) ◽  

Abstract DELORO 716 PM is a nickel-base alloy recommended for handling conditions of wear, erosion, heat and corrosion when impact is also a consideration. This datasheet provides information on composition, physical properties, and hardness. It also includes information on high temperature performance and wear resistance as well as machining and joining. Filing Code: Ni-435. Producer or source: Deloro Stellite Inc.


Alloy Digest ◽  
1965 ◽  
Vol 14 (11) ◽  

Abstract MAR-M Alloy 200 is a nickel-base alloy designed primarily as a cast turbine blade material which retains useful strength up to 1900 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as heat treating and joining. Filing Code: Ni-107. Producer or source: Martin Metals Company.


Alloy Digest ◽  
1965 ◽  
Vol 14 (4) ◽  

Abstract INCONEL Alloy 722, formerly Inconel W alloy, is a high strength, high-temperature nickel-base alloy responding to age hardening heat treatments for maximum properties. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-100. Producer or source: Huntington Alloy Products Division, An INCO Company.


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