磁控溅射Al-Zr薄膜在微拉深成形中的拉深性能(英文)

拉深成形可以用来制备形状复杂的零部件,甚至可达微加工水平。采用磁控溅射方法,在基底温度分别为310K和433K下,制备了厚度约为15μm的两种不同的AlZr薄膜。将这两种薄膜做为坯料,采用冲头直径为0.75mm的微拉深设备研究其拉深性能。虽然这两种材料在拉伸试验中显示出较小的最大应变,但还是成功地实现了微拉深成形。在基底温度为310K和433K制备的两种材料的极限拉深比分别为1.8和1.7。这些结果比先前采用AlSc合金的结果要好,与采用传统轧制方法所得纯铝薄膜的拉深结果相似。结果表明,采用磁控溅射方法制备的薄膜可以用来进行微拉深成形。

Influence of Substrate Bias Voltage on the Properties of Sputtered Aluminum-Scandium Thin Sheets

Thin sheets (20 μm - 30 μm) of an aluminum-scandium alloy were manufactured by magnetron sputtering with a homogeneous thickness distribution. The influence of bias voltage on the sheet properties was investigated. Steel sheets of 100 μm were employed as substrate and were coated in a dc magnetron sputtering unit fitted with a rectangular target of aluminum 2.0 w% scandium master alloy. After deposition, the substrates were dissolved in an oxidizing medium and thus freestanding aluminum-scandium thin films were obtained. The homogeneous thickness was achieved by a reciprocal movement of the substrate. The influence of a radio frequency bias voltage on the coating properties was investigated. The bias voltage resulted in an important coarsening of the columnar structure as well as an increase of the roughness and hardness. Additionally, a low bias voltage could intensively reduce the coating defect density without altering too much the sheet properties.