English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

As part of a study to investigate the fatigue behavior of the intermetallic compound NiAl near its monotonic brittle-to-ductile transition temperature (BDTT), prealloyed stoichiometric NiAl powders were hot extruded and fabricated into tensile and fatigue specimens. From the monotonic tests conducted at a nominal strain rate of lo4 sect, the BDTT was found to be approximately 650 K. Low cycle fatigue (LCF) tests were performed at 600, 675, and 700 K at plastic strain ranges of 0.005 and 0.01. The percentage of intergranular failure decreased in the fracture morphology of both the monotonic and fatigue tests. For all temperatures and strain ranges in this study, rapid hardening was observed for up-to 15 cycles, after which the peak stress increased only slightly for the remainder of the life. As test temperature was increased or strain range decreased, both the initial hardening rate and relative saturation stress decreased. Additionally, slip traces were observed on the gage surfaces of all LCF specimens. In fatigue specimens, secondary cracks were found in the gage section near the eventual fracture site. Transgranular surface cracks apparently resulted from slip intrusions/extrusions. Intergranular surface cracks were seen that could result from planar slip pile-ups at grain boundaries, however other mechanisms have not been ruled out. No significant improvement in life at a strain range of 0.005 was observed when the test temperature was increased from 600 to 700 K, a change which corresponds to an increase in monotonic tensile ductility from 2 to 18%. Apparently, a cyclic brittle-to-ductile transition did not occur in this temperature range. If thermally activated deformation affects fatigue lives as it does monotonic ductility, the cyclic transition temperature is higher than the monotonic BDTT. More work is necessary to precisely identify the deformation mechanisms that operate in low cycle fatigue of NiAl. Superalloys 1992 Edited by S.D. Antolovich, R.W. Stusrud, R.A. MacKay, D.L. Anton, T. Khan, R.D. Kissinger, D.L. Klarstrom The Minerals, Metals & Materials Society, 1992

Low Cycle Fatigue of NiAl Deformed Near the Brittle-to-Ductile Transition Temperature