A New Approach for Preparing SiC Particle-reinforced Aluminum Matrix Composites by Applying Electromagnetic Field

A new method for preparing SiC particle-reinforced aluminum matrix composites was introduced.In order to improve the ingot surface and homogeneity of structure,low frequency electromagnetic field was applied during the direct chilling casting process.The experimental results show that the new method can be used to prepare SiC particle-reinforced aluminum matrix composites;under the effects of the low frequency electromagnetic field,the microstructure of ingot is refined and the distribution of SiC particles is improved.

Improvement of thickness uniformity and elements distribution homogeneity for multicomponent films prepared by coaxial scanning pulsed laser deposition technique

In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.