On the relationship between grain boundary sliding and crystal deformation

Tungsten wire for incandescent lamp filaments must operate at high temperatures and for long times. To meet these requirements, the grain morphology of the wire must be controlled to reduce the propensity for grain boundary sliding. The morphology is a function of the distribution of very small pockets of potassium in the wire and the mechanical processing from ingot to wire. The behavior of the filament is directly related to the grain morphology. This paper describes the mechanism by which the potassium is incorporated into and distributed in the ingot. The elongation and spheroidization of the bubbles during hot rolling and swaging are also examined and related to the grain morphology of wire. Some indications of the relationship between grain morphology and filament behavior are also given.

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On the Relationship Between Grain Boundary Sliding and Intragranular Slip During Superplastic Deformation

MRS Proceedings ◽

10.1557/proc-601-193 ◽

1999 ◽

Vol 601 ◽

Cited By ~ 1

Author(s):

A. D. Sheikh-Ali ◽

J. A. Szpunar ◽

H. Garmestani

Keyword(s):

Plastic Strain ◽

Grain Boundary ◽

Superplastic Deformation ◽

Theoretical Estimate ◽

Grain Boundary Sliding ◽

Polycrystalline Materials ◽

Boundary Sliding ◽

The Relationship

AbstractThis paper examines grain boundary sliding under the conditions of plastic strain incompatibility that is the most frequent case in polycrystalline materials. Two components of grain boundary sliding: dependent and independent on intragranular slip are distinguished. Theoretical estimate of a ratio between slip induced sliding and intragranular slip is obtained. It is concluded that slip and sliding are rather independent than interrelated processes.

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The effect of microstructure on the relationship between grain boundary sliding and slip transmission in high purity aluminum

International Journal of Plasticity ◽

10.1016/j.ijplas.2020.102818 ◽

2020 ◽

Vol 135 ◽

pp. 102818

Author(s):

Marissa A. Linne ◽

Thomas R. Bieler ◽

Samantha Daly

Keyword(s):

Grain Boundary ◽

High Purity ◽

Grain Boundary Sliding ◽

High Purity Aluminum ◽

Boundary Sliding ◽

The Relationship ◽

Effect Of Microstructure ◽

Slip Transmission

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Examination of Fracture Interfaces in Silicon Nitride

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113925 ◽

1975 ◽

Vol 33 ◽

pp. 60-61

Author(s):

Nancy J. Tighe

Keyword(s):

Silicon Nitride ◽

Grain Boundary ◽

Crack Growth ◽

Subcritical Crack Growth ◽

Slow Crack Growth ◽

Ceramic Materials ◽

Grain Boundary Sliding ◽

Boundary Phase ◽

Turbine Engines ◽

Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

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