铝阳极化冲击波探针的工艺探索

A Kind of Anodized Aluminium Shock Wave Detectors

为了在定形纯铝棒材(35mm× 1.0mm)上制取既薄、完整,又均匀、致密且电绝缘强度较高的绝缘膜,首先根据阳极化电解原理,测定了铝棒半球形端的极化曲线,获得了在50～60℃温度环境下铝绝缘膜稳定生长的区域在3～13V之间这一重要的工艺条件;然后给出了铝电探针阳极化的步骤和相应的工艺参数。从而摸索出可批量生产适于液体冲击压缩实验的、性能一致性好、可靠性高的冲击波速度探测器的实验方法。同时,分析了电解系统温度条件以及沸水封孔工艺对强化铝绝缘膜的物理性质和电绝缘强度的影响。由此工艺可均匀地制得厚度在4～15μm之间的Al2O3薄膜,在给定温度下制得平均厚度为6μm的电探针耐直流电压为250V、1min,在液氮温度(77K)下静置4h后绝缘膜的物理外观和电绝缘强度都未发生变化。借助300N·m冲击力发生器,测得该类探针的开关一致性不大于±20ns。在较高冲击压力下,该特性有望得到进一步改善。

For making a layer of insulated film,which are both thin,intact,even,compact,and with a higher electric insulating intensity,on a shaped pure aluminium wire(35 mm in length and 1 mm in diameter),we first measured a polarized curve of one half hemispherical end of the aluminium wire based on the anodization principle,and obtained an important technical condition that the aluminium insulated film can be grown steadily in the region of 3 ～13 V at the environment temperature of 50～60 ℃.And then,we confirmed a series of applied operating steps and relevant technical parameters.Therefore,a good experimental recipe,which can be used to direct mass-producing shockwave velocity detectors with a good performance in coherence and reliability,has been determined naturally.At the same time,the influences of temperature condition in electrolysis system and sealing method with boiling water on the film's physical quality and electric insulating intensity were revealed.With the technique,a Al_2O_3 film of 4～15 μm has been made uniformly,which possesses insulating ability of D.C 250 V for 1 min duration.Furthermore,the physical appearance and electric insulating intensity of these detectors are undistinguishable,relative to the original when put them into the liquefied nitrogen for 4 h.The switched on and off consistencies of these probes are measured to be not over ±20 ns tested by an impacter forging hammer of 300 N·m.Actually,the performance will be further improved under a higher shock pressure.