Effects of Cr Addition on the Microstructure and Mechanical Properties of an Al-Si-Cu-Mg Alloy.

The effects of chromium (Cr) addition ranging 0.1-0.3 wt.% on the microstructure and mechanical properties of Al-7Si-4Cu-0.25Mg (wt.%) alloy have been investigated. The cast Cr-free alloy consisted of α-Al, eutectic Si, Q-Al5Mg8Cu2Si6 and θ-Al2Cu phases. Doping of Cr resulted in the appearance of a polyhedron-shaped α-Al13Cr4Si4 phase with a cubic structure. The Al13Cr4Si4 particles were found to embed with Al2Cu blocks and bring about size reduction for the Al2Cu blocks. The area fraction of Al13Cr4Si4 monotonously increased with Cr content. After T6 treatment, the Al2Cu blocks almost fully dissolved and transformed to θ'-Al2Cu precipitates in the Cr-containing alloys. TEM observation revealed relatively large-sized θ' precipitates attached to Al13Cr4Si4 dispersoids. The Cr-containing alloys showed impressive mechanical properties, with the peak strength up to 452 MPa at room temperature. The ductility exhibited an increasing trend with Cr content, but the strength dropped dramatically when the Cr content reached 0.3 wt.%. It is suggested that the strength contribution from the Al13Cr4Si4 phase is limited, especially at an elevated temperature.

Enhanced adsorption dynamics and thermal stability of radioactive Sr(II) by lamellar Nb-doped sodium vanadosilicate via self-assembly and conditional natroxalate intercalation.

To promote the environmentally friendly and sustainable development of nuclear energy, it is imperative to address the treatment of wastewater generated by the nuclear industry. This necessitates the enhancement of fission product reclamation efficiency post-treatment. This study aims to combine defect control and confined self-assembly strategies for the precise design of interlayer spacing (14.6 Å to 15.1 Å), leading to the fabrication of conditional natroxalate-functionalized vanadosilicate, and its potential application in the efficient adsorption and reclamation of 90Sr. Na0.03Natroxalate2.47Si1.44Nb0.08V1.92O5·1.2 H2O (Nb4-NxSiVO), with a layer spacing of 14.9 Å, exhibits the highest Sr(II) adsorption capacity (248.76 mg/g), enabling effective separation with Cs+. The natroxalate embedded within the confined interlayers demonstrates excellent stability, offering rapid (within 10 min) and stable adsorption sites for Sr(II). Furthermore, Nb4-NxSiVO exhibits a wide band gap and exceptional thermal stability before and after adsorption, rendering hard desorption of 90Sr. The findings highlight the potential of Nb4-NxSiVO as a promising adsorbent for rapid and selective purification of 90Sr-containing wastewater and further application in nuclear batteries.