Effect of equal channel angular pressing on microstructure, texture, and high-cycle fatigue performance of wrought magnesium alloys

2009 ◽  
Vol 100 (6) ◽  
pp. 838-842 ◽  
Author(s):  
Julia Müller ◽  
Miloš Janeček ◽  
Sangbong Yi ◽  
Jakub Čížek ◽  
Lothar Wagner
Keyword(s):  
Magnesium Alloys ◽  
Equal Channel Angular Pressing ◽  
High Cycle Fatigue ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Angular Pressing

High cycle fatigue behavior of Al1070 alloy severely deformed by equal channel angular pressing process

2016 ◽  
Vol 232 (6) ◽  
pp. 514-519 ◽  
Author(s):  
Mohammad Bagher Limooei ◽  
Morteza Zandrahimi ◽  
Ramin Ebrahimi
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Equal Channel Angular Pressing ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Pure Aluminum ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Angular Pressing ◽  
Pressing Process

In the present work, equal channel angular pressing of commercial pure aluminum 1070 was performed up to 4 passes using route Bc. For equal channel angular pressing operation, a suitable die set was designed and manufactured. X-ray diffraction analysis was used to determine the microstructure of the equal channel angular pressing-ed material. The fracture surface morphology and microstructure after fatigue were investigated by scanning electron microscopy. Mechanical properties of the equal channel angular pressing-ed material were evaluated by hardness and tension tests. Also, cyclic deformation behavior of severe plastic deformation Al1070 has been studied and results show a significant variation in hardness, ultimate strength and fatigue properties in high cycle fatigue life. Coefficient of fatigue strength σ′f and Bridgman correction factor have been obtained by S-N curve and tension test specimens, respectively, and compared before and after equal channel angular pressing process. Also an useful relation has been derived between fatigue life ( Nf) and stress amplitude ( σa) in high cycle fatigue region. Results indicated that there was not clear relation between fatigue strength coefficient and true corrected fracture stress in this case.

Effect of Trace Impurities on High-Cycle Fatigue Damage of Ultrafine Grained Copper Processed by Equal Channel Angular Pressing

2008 ◽  
Vol 584-586 ◽  
pp. 809-814
Author(s):  
Masahiro Goto ◽  
N. Teshima ◽  
Seung Zeon Han ◽  
T. Yakushiji ◽  
Sang Shik Kim
Keyword(s):  
Equal Channel Angular Pressing ◽  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Surface Damage ◽  
Cycle Fatigue ◽  
Trace Impurities ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Two Samples ◽  
Formation Behavior

In order to study the effect of trace impurities on high-cycle fatigue damage of ultrafine grained (UFG) copper, fatigue tests were carried out for two samples: oxygen-free copper (OFC, 99.99 wt% Cu) and deoxidized low-phosphorous copper (DLP, 99.95 wt% Cu). After the processing by equal channel angular pressing (ECAP) using eight passes, equiaxed grains with an average size of 250 nm were formed for both the samples. Fatigue strength of UFG copper was enhanced by the impurities. The formation behavior of surface damage and the change in surface hardness was monitored. A close relationship was observed between the change in hardness and the formation behavior of surface damage. The physical background of the effect of trace impurities on the fatigue damage was discussed from the viewpoints of surface damage formation behavior.

Effect of Heat Treatment on Very High Cycle Fatigue Properties of TC4

2021 ◽  
Vol 881 ◽  
pp. 3-11
Author(s):  
Bo Han Wang ◽  
Li Cheng ◽  
Xun Chun Bao
Keyword(s):  
Heat Treatment ◽  
High Cycle Fatigue ◽  
Treatment Method ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Α Phase ◽  
Very High Cycle Fatigue ◽  
Significant Difference ◽  
Very High

The bimodal, equiaxed and Widmanstatten microstructures of TC4 titanium alloy were obtained through different heat treatment processes. The content of primary α phase in the bimodal and equiaxed microstructures was measured to be about 40% and 90%, and the average size was about 9.4μm and 7.9 μm. Three types of microstructure fatigue S-N curves are obtained, which are successively descending type, single-platform descending type and infinite life type. The order of very high cycle fatigue performance is Widmanstatten>equiaxed>bimodal, but the anti-fretting fatigue performance of Widmanstatten is the worst. The grain refinement makes the fatigue performance of the equiaxed better than that of the bimodal. The second process is determined as the best heat treatment method. There is no significant difference in the life of the crack propagation stage. The very high cycle fatigue life mainly depends on the crack initiation stage. In the bimodal and the equiaxed, the crack initiates in the primary α phase of the subsurface, and the crack in the Widmanstatten initiates in the coarse α 'grain boundary of the subsurface.

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