scholarly journals Effects of Solution Treatment on Microstructure and High-Cycle Fatigue Properties of 7075 Aluminum Alloy

Metals ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 193 ◽  
Author(s):  
Chi Liu ◽  
Yilun Liu ◽  
Liyong Ma ◽  
Jiuhuo Yi
2014 ◽  
Vol 217-218 ◽  
pp. 227-234 ◽  
Author(s):  
Alain Abou Antoun ◽  
Myriam Brochu ◽  
Heinrich Möller

Two objectives were targeted: 1) compare the high cycle fatigue behavior of rheocast aluminum alloy 357 prepared by the swirl enthalpy equilibration device (SEED) and by the Council for Scientific and Industrial Research (CSIR) process, and 2) study the effect of surface liquid segregation (SLS) on the fatigue behavior of the CSIR material. Rectangular hourglass specimens machined from rheocast plates were tested at four stress amplitudes in axial fatigue with a stress ratio of R = -1 and a frequency of 20 Hz. Results obtained for SLS free specimens show that the SEED and the CSIR processes produce rheocast materials with comparable high cycle fatigue properties, 115 MPa at 107 cycles. In order to study the influence of surface liquid segregation, slightly polished specimens with a remaining SLS of nearly 750 microns thick were also tested. According to the results, the SLS reduces the average fatigue strength by approximately 5% (110 MPa vs. 115 MPa at 107 cycles). For SLS free specimens, the fatigue crack initiated at shrinkage cavities, oxide films or in the alpha globules. On the other hand, for specimens with SLS, no crack initiation in the alpha globules was observed. The main crack initiation mechanism was identified to be a deformation incompatibility between regions characterized by higher silicon content compared to nominal eutectic regions. The originality of the work is provided by the rigorous comparative analysis of the fatigue performance of components produced in two different rheocasting facilities, but tested in a single laboratory. It is also the first fundamental research published on the mechanical effect of surface liquid segregation. It confirms that SLS should be removed in critical areas in order to optimize the fatigue resistance of rheocast components.


2005 ◽  
Vol 54 (12) ◽  
pp. 1255-1261 ◽  
Author(s):  
Kiyotaka MASAKI ◽  
Youhei KUMAGAI ◽  
Yasuo OCHI ◽  
Takashi MATSUMURA ◽  
Tatsuhiko HAMAGUCHI

2014 ◽  
Vol 598 ◽  
pp. 243-248 ◽  
Author(s):  
Tomasz Tomaszewski ◽  
Janusz Sempruch

In special situations the fatigue properties of the construction material can be determined using non-standard specimens, for example smaller than the normative ones (the so-called mini specimens). The research presented was made for the aluminum alloy based on the high-cycle fatigue testing methodology. The verification was made by breaking down the results with own tests which involved the use of standard specimens and stands as well as with the literature reports.


2020 ◽  
Vol 2020 (0) ◽  
pp. J03104
Author(s):  
Yusuke KAWABATA ◽  
Yoshimasa TAKAHASHI ◽  
Masanori TAKUMA ◽  
Ken-ichi SAITOH ◽  
Tomohiro SATO

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