If we conduct a tensile test of aluminum alloy samples in vacuum and atmospheric pressure, there will be a difference in the values of tensile strength, yield strength and elongation.
Dear Dr. Sergey Voronin ,
I suggest you to have a look at the following papers, hoping that they are useful for the evaluation of your research data:
-The Effect of Vacuum on the Mechanical Properties of Die Cast Aluminum AlSi9Cu3(Fe) Alloy
International journal of metalcasting (2019)
Szalva Péter, Imre N. Orbulov
Available directly on Research Gate at: https://www.researchgate.net/publication/330097143_The_Effect_of_Vacuum_on_the_Mechanical_Properties_of_Die_Cast_Aluminum_AlSi9Cu3Fe_Alloy
And at: http://real.mtak.hu/89281/1/IJMC-D-18-00211_R2_REAL.pdf
-Microstructure and Mechanical Properties of High Vacuum Die-Cast AlSiMgMn Alloys at as-Cast and T6-Treated Conditions
Fei Liu, Haidong Zhao, Runsheng Yang, and Fengzhen Sun
Materials, 12(13): 2065 (2019)
Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6651273/
-The influence of different vacuum degree on the porosity and mechanical properties of aluminum die casting
Vacuum, 146 (2017)
Cao Han-xue, Hao Meng-yao,Shen Chao, Liang Peng
Available directly on Research Gate at:
https://www.researchgate.net/publication/320140141_The_influence_of_different_vacuum_degree_on_the_porosity_and_mechanical_properties_of_aluminum_die_casting
Best regards, Pierluigi Traverso.
There may not be any difference in mechanical properties if the tensile test is carried out at a normal strain rate of about 1E-3 per second. However, slow strain rate tensile tests (slower than 1E-7 per second) and fatigue tests carried out in vacuum may lead to a marginally increased mechanical behavior as compared to their ambient counterparts. This is related to enhanced oxidation of crack tip at atmospheric pressure and relative humidity. Nothing to do with the hydrostatic pressure imposed by the vacuum chamber.
Pierluigi Traverso thanks for the answer! But I'm interested in the effect of vacuum on the mechanical properties of the finished material, not in the process of casting.
Abdul Malik
Thanks for the answer! Why do you think that there will be no effect of vacuum on the mechanical properties of the material?
Krishnan Raja Thanks for the answer! I completely agree with you, the difference in properties will be at low strain rates. Could you recommend articles on this subject? And what do you think of the degassing processes in aluminum alloys?
Completely agree with Dr Raja.... Generally speaking, fatigue life of Al alloys is strongly affected than the fatigue crack propagation rate when tested under high vacuum. Tensile properties as well as fracture toughness are relatively insensitive unless you test extremely slowly. you can refer to several articles on fatigue properties such as
1) Article Fractography of fatigue crack propagation in 2024-T3 and 707...
2)Article Fatigue behavior of die casting aluminum alloys in air and vacuum
3) Article Environmental Effects on Fatigue Crack Growth in 7075 Aluminum Alloy
I am sure you will get more relevant literature if you consult these references...