Creep Behavior of a Zirconium Alloy Processed by Equal-Channel Angular Pressing

Abstract

A Zr2.5 wt%Nb alloy was processed by equal-channel angular pressing and then tested under creep conditions at 623 K using a tensile stress within the range from 120 to 300 MPa. The results show conventional power-law creep with a stress exponent of n > 3 which is consistent with an intragranular dislocation process involving the glide and climb of dislocations. It is demonstrated that diusion creep is not important in these tests. For comparison purposes, the experiments were conducted using both the unprocessed alloy and after processing by equal-channel angular pressing. It was found that under same testing conditions the measured minimum creep rates in the pressed alloy with ultrane grain sizes were faster than in the same alloy in a coarse-grained unprocessed condition.

Creep properties of aluminium processed by ECAP

“…In our previous works [12][13][14][15][16][17], it was found that the sample after 1 ECAP pass exhibited the highest creep resistance. This suggests that the highest creep resistance can be achieved in inhomogeneous ECAP-processed microstructure containing a high density of LAGBs but a lower density of HAGBs.…”

“…Creep in polycrystalline materials after SPD processing was investigated on pure metals [10][11][12][13][14][15][16], alloys [17][18][19][20], and Cu-Al 2 O 3 composite [21]. However, there are a few reports documenting the creep properties and creep mechanisms of the ultrafine-grained (UFG) materials processed by different numbers of ECAP passes.…”

ACOM/TEM and EBSD Microstructure Characterization of ECAE-Processed Zirconium

“…The microstructure analysis was conducted with BF TEM image and SAD diffraction. Sklenicka (2012) [17] studied the microstructure of Zr-2.5Nb with EBSD, and they commented that the grain sizes were not fully investigated due to the limited resolution in the characterization of the very small grains by the EBSD method. An investigation of the formation of ZrO in the zirconium structure by TKD and TEM showed that they are complementary techniques [18].…”

Дефектная Структура И Термомеханическая Стабильность Нано- И Микрокристаллического Титана, Полученного Разными Методами Интенсивной Пластической Деформации

“…1). Однако, как показал анализ данных настоящей работы и литературных дан-ных, степень повышения σ B , σ S , H v может значительно отличаться от полученной для долговечности (известны случаи, когда τ после перевода образца в микрокристал-лическое состояние даже уменьшается) [10,[12][13][14][15][16][17].…”