عنوان مجله
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METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
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چکیده
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Since the last decade, the fabrication of ultrafine grain and nanostructure metals and alloys has
attracted much attention in the field of materials engineering. The present study aimed at
experimentally investigating the fatigue properties that are of great importance in dynamic
structures before and after the planar twist extrusion process for both commercially pure copper
and 6061 aluminum alloy. The results indicated that the yield strength, tensile strength,
hardness, and fatigue endurance of copper increased by about 398, 122, 198, and 183 pct,
respectively, while they improved by about 429, 212, 227, and 148 pct, respectively, in aluminum
alloy as compared to the initial conditions. The stress-strain curves displayed sizable reduction
of strain hardening. Furthermore, grain-size correction factors based on the empirical results
were introduced to include the effect of the grain-size effect on both low and high-cycle fatigue
strengths of the material.
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