Grain size dependence of fracture toughness for fine grained alumina

2011 ◽  
Vol 65 (2) ◽  
pp. 143-146 ◽  
Author(s):  
Wenlong Yao ◽  
Jing Liu ◽  
Troy B. Holland ◽  
Lin Huang ◽  
Yuhong Xiong ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Size Dependence ◽  
Fine Grained

scholarly journals Grain Size Dependence of Fracture Toughness in an Ultrahigh Strength Maraging Steel

1983 ◽  
Vol 69 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Yoshikuni KAWABE ◽  
Seiichi MUNEKI ◽  
Junji TAKAHASHI
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Maraging Steel ◽  
Size Dependence ◽  
Ultrahigh Strength

Crack Dynamics and Grain Size

1994 ◽  
Vol 362 ◽  
Author(s):  
John J. Gilman
Keyword(s):  
Grain Size ◽  
Kinetic Energy ◽  
Sound Speed ◽  
Maximum Stress ◽  
Size Dependence ◽  
Terminal Velocity ◽  
Moving Crack ◽  
Fine Grained ◽  
Crack Dynamics ◽  
Relative Kinetic

AbstractTwo aspects of fast cracks are considered: 1. the terminal velocity, and corresponding relative kinetic energy; 2. the grain size dependence of the fracture. It is argued that this is determined by the kinetic energies of cracks when they have expanded enough to reach the boundaries of the grains in which they lie. This is more consistent with the observed facts than the more usual quasi-static models.By considering the limiting conditions at the very tip of a moving crack, many complications are avoided in calculating the terminal velocity. The maximum transverse acceleration of material is limited by the maximum stress (cohesive) that can be applied. The resulting terminal velocity is: 0.4 vs, where vs is the longitudinal sound speed; compared with measured values which average about: 0.31 vs.In polycrystals, microcracks are found when the applied stress exceeds the yield stress. However, the microcracks do not propagate in fine-grained specimens because they do not have enough kinetic energy to cross a typical grain boundary. This leads to the observed dependence of the fracture stress on the grain size.

Observation of slip propagation across grain boundaries in Ni3Al

1986 ◽  
Vol 44 ◽  
pp. 864-865 ◽  
Author(s):  
I. Baker ◽  
E.M. Schulson ◽  
J.A. Horton
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Room Temperature ◽  
Size Dependence ◽  
Direct Evidence ◽  
Specimen Preparation ◽  
Fine Grained ◽  
Room Temperature Yield Strength ◽  
Pile Up ◽  
Preparation Techniques

Recent modelling of the grain size dependence of the room-temperature yield strength of Ni3Al has invoked the concept of dislocation pile-ups. The idea is that the yield strength measured in the Liiders regime (i.e. the Liiders band propagation stress) represents not the stress to independently nucleate slip in each grain but the stress required to propagate slip through the material. This paper presents direct evidence of slip propagation from one grain to the next and thus validation of the use of a pile-up model for Ni3Al.Miniature tensile specimens (3 mm x 7 mm x0.2 mm), made from an extruded rod of fine-grained (∽10 μm) Ni3Al containing 0.35 at.% boron, were strained under tension whilst being observed in a Philips EM 430T operated at 300 KV. Details of the design and operation of the straining stage and of the specimen preparation techniques are given elsewhere.

The grain size dependence of fracture toughness in an Al-6.0% Zn-2.5% Mg alloy

1978 ◽  
Vol 13 (5) ◽  
pp. 945-950 ◽  
Author(s):  
Takeshi Kawabata ◽  
Osamu Izumi
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Size Dependence ◽  
Mg Alloy

Grain-size dependence of cleavage fracture toughness in mild steel

Nature ◽  
1978 ◽  
Vol 276 (5683) ◽  
pp. 50-51 ◽  
Author(s):  
D. A. CURRY
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Mild Steel ◽  
Cleavage Fracture ◽  
Size Dependence

scholarly journals Grain Size Dependence of the Fracture Toughness of Silicon Nitride Ceramics

1991 ◽  
Vol 99 (1148) ◽  
pp. 320-323 ◽  
Author(s):  
Takeshi KAWASHIMA ◽  
Hiromi OKAMOTO ◽  
Hideharu YAMAMOTO ◽  
Akira KITAMURA
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Silicon Nitride ◽  
Size Dependence ◽  
Nitride Ceramics
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