Mechanical behavior of nanostructured bulk aluminum at various temperatures

The mechanical behavior of nanostructured bulk aluminum samples processed by means of ball milling and hot consolidation was investigated at various temperatures. Stress-Strain Microprobe^® system and its Automated Ball Indentation^® (ABI^®) test were used for non-destructive determination of the mechanical properties of nanostructured Al samples under various variables. High purity aluminum was processed by means of ball milling for 6 hours and ball to powders weight ratios (BPR) of 30:1 and 90:1. The sintered bulk Al samples were subjected to ABI tests at room temperature, 200 °C and 400 °C to investigate the effect of BPR and test temperature on the mechanical behavior of these samples. Aluminum samples (C90-RT) which were ball milled using high BPR of 90:1 and tested at room temperature displayed the greatest values of final indentation load (303; ± 10 N); YS (228 ± 9 MPa); UTS (394 ± 11 MPa) and ABI hardness value of 113 ± 4, as compared to all samples under examination. On the other hand, the samples tested at 400 °C (C90-400 sample) revealed the least values of final indentation load (156 ± 4 N); YS (113 ± 1 MPa); UTS (220 ± 4 MPa) and ABI hardness value of 61. (paper)