Modified strain rate regime in ultrafine grained copper with silver micro-alloying

作者：Champion Y^*; Bourgon J; Sauvage X

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2016, 657: 1-5.

DOI：10.1016/j.msea.2016.01.044

• Ultrafine grained
• Copper
• Silver
• Micro-alloying
• Strength
• Strain rate

Ultrafine grained (UFG) copper with an average grain size of 115 nm was micro-alloyed with silver (UFG CuAg) to analyze its effect on strain rate sensitivity. The materials were prepared by sintering Ag microalloyed-Cu ultrafine powder, using the spark plasma sintering (SPS) technique and after H-2 pre-annealing for oxide reduction. Mechanical tests show that UFG CuAg follows the law of behavior established for UFG Cu: m approximate to B(1 - sigma(0)/sigma), relating the strain rate sensitivity m and the applied stress, sigma. In this relation, sigma(0) is a threshold grain size dependent stress and B is characterizing the grain boundaries diffusion properties. Main difference compared to pure UFG copper is a large value of the parameter B for UFG CuAg, indicating a dominant role of the grain boundaries structure and chemistry on the rheology of UFG metals.

• 出版日期2016-3-7