Simulation of Anisotropic Steady-State Creep Behavior of Multi-Crystal SnAgCu Joints

2021 ◽  
Author(s):  
Qian Jiang ◽  
Abhishek Deshpande ◽  
Abhijit Dasgupta
Keyword(s):  
Steady State ◽  
Creep Behavior ◽  
Steady State Creep

Steady-state creep behavior of hot isostatically pressed niobium carbide

1987 ◽  
Vol 22 (9) ◽  
pp. 1233-1240 ◽  
Author(s):  
R.D. Nixon ◽  
S. Chevacharoenkul ◽  
R.F. Davis
Keyword(s):  
Steady State ◽  
Creep Behavior ◽  
Niobium Carbide ◽  
Steady State Creep

The Investigation of Creep Behavior for NiAl-28Cr-5.5Mo-0.5Hf-0.02wt.%P Alloy at High Temperature

2011 ◽  
Vol 279 ◽  
pp. 28-32
Author(s):  
Guang Ye Zhang ◽  
Dong Wen Ye ◽  
Jin Lin Wang ◽  
You Ming Chen ◽  
Long Fei Liu ◽  
...  
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Creep Behavior ◽  
Fracture Behavior ◽  
Primary Creep ◽  
Dislocation Climb ◽  
Steady State Creep ◽  
Creep Fracture ◽  
Creep Mechanisms ◽  
Higher Temperature

The Microstructure and creep behavior for NiAl-28Cr-5.5Mo-0.5Hf-0.02wt.%P alloy at high temperature have been investigated in this paper. The results reveal that the high temperature creep behavior of the NiAl-28Cr-5.5Mo-0.5Hf-0.02wt.%P alloy is characterized by transient primary creep and dominant steady-state creep as well as ternary creep behavior. The primary creep can be described by Garofalo equation and the steady-state creep can be depicted by Dorn equation. The creep mechanisms are viscous glide of dislocations at lower and middle testing temperatures and dislocation climb at higher temperature. No change of the microstructure for the testing alloy indicates that the creep fracture is controlled by the formation and propagation of cavities and cracks, and the creep fracture behavior obeys Monk man-Grant relationship.

Improved tensile creep properties of yttrium- and lanthanum-doped alumina: a solid solution effect

2001 ◽  
Vol 16 (2) ◽  
pp. 425-429 ◽  
Author(s):  
Junghyun Cho ◽  
Chong Min Wang ◽  
Helen M. Chan ◽  
J. M. Rickman ◽  
Martin P. Harmer
Keyword(s):  
Solid Solution ◽  
Steady State ◽  
Creep Behavior ◽  
Solubility Limit ◽  
Steady State Creep ◽  
Tensile Creep ◽  
Creep Properties ◽  
Uniform Microstructure ◽  
Equiaxed Grains ◽  
Rare Earth Doped

The tensile creep behavior of yttrium- and lanthanum-doped alumina (at dopant levels below the solubility limit) was examined. Both compositions (100 ppm yttrium, 100 ppm lanthanum) exhibited a uniform microstructure consisting of fine, equiaxed grains. The creep resistance of both doped aluminas was enhanced, compared with undoped alumina, by about two orders of magnitude, which was almost the same degree of improvement as for materials with higher dopant levels (in excess of the solubility limit). In addition, measured creep rupture curves exhibited predominantly steady-state creep behavior. Our results, therefore, verified that the creep improvement in these rare-earth doped aluminas was primarily a solid-solution effect.

Effect of Ag and Cu Concentrations on Creep of Sn-Based Solders

2007 ◽  
Author(s):  
T. Chen ◽  
I. Dutta ◽  
S. Jadhav
Keyword(s):  
Steady State ◽  
Creep Behavior ◽  
Volume Fraction ◽  
Steady State Creep ◽  
Β Phase ◽  
Diffusion Controlled ◽  
Microstructural Constituent ◽  
Solder Balls ◽  
Rate Limiting ◽  
Pure Sn

The creep behavior of Sn1Ag0.5Cu, Sn2.5Ag1Cu and Sn4Ag0.5Cu ball grid array (BGA) solder balls and 99.99% pure polycrystalline Sn bulk was studied using impression creep. The microstructures of the as-reflowed solders was characterized. It was found that SnAgCu solders consist of primary dendrites/grains of β-Sn, and a eutectic microconstituent comprising fine Ag3Sn and Cu6Sn5 particles in β. With increasing concentrations of Ag and Cu in the alloy, the proportion of the eutectic microconstituent in relation to the primary β phase increases. In pure Sn and Sn-1Ag-0.5Cu, the β grains form the continuous matrix, whereas in Sn2.5Ag1Cu and Sn4Ag0.5Cu, the eutectic microconstituent forms a continuous network around the β grains, which form isolated islands within the eutectic. The steady state creep behavior of the alloys was dominated by the response of the continuous microstructural constituent (β-Sn or solid solution β for pure Sn and Sn1Ag0.5Cu, and the eutectic microconstituent for Sn2.5Ag0.5Cu and Sn4Ag0.5Cu). In general, the steady-state creep rate decreased with increased alloy content, and in particular, the volume fraction of Ag3Sn and Cu6Sn5 precipitates. The rate-limiting creep mechanism in all the materials investigated here was core diffusion controlled dislocation climb. However, subtle changes in the stress exponent n and activation energy Q were observed. Pure Sn shows n = 5, Q = 42kJ/mole, Sn1Ag0.5Cu shows n = 5, Q = 61kJ/mole, whereas both Sn2.5Ag1Cu and Sn4Ag0.5Cu show n = 6 and Q = 61kJ/mole. Rationalizations for the observed changes of n and Q are provided, based on the influence of the microstructure and the solute concentrations.

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