P3Q-1 Ultra Precision Grinding in the Fabrication of High Frequency Piezocomposite Ultrasonic Transducers
P3Q-1 Ultra Precision Grinding in the Fabrication of High Frequency Piezocomposite Ultrasonic Transducers
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P3Q-1 高频压电复合材料超声波换能器制造中的超精密磨削
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
J. Sweet
中科院分区：
文献类型：
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作者：
S. Cochran;D. MacLennan;Tim W. Button;H. Hughes;M. Ponting;J. Sweet
在医学诊断和无损检测等应用中，需要高频超声换能器来进行高空间分辨率的测量。然而，具有20 MHz以上频率的高性能换能器的成本效益的制造是具有挑战性的，因为需要活性材料的薄层。压电复合材料是此类低频换能器的首选材料，但目前的制造方法无法轻松实现足够薄的有源层。在商业上，压电复合材料通常通过磨削加工到一定厚度，从而提供大多数应用可接受的表面光洁度。然而，传统的研磨对于高频操作来说不够精确，并且受到不期望的工艺内变化的影响。最广泛使用的替代方法是精密研磨和抛光，但这是缓慢的，因此昂贵。在这里报道的工作中，研究了超精密磨削的替代工艺，使用在延性加工模式下操作的Loadpoint PicoAce机床。为了确定该机器用于压电复合材料加工的能力，使用标准商业工艺和基于粘性聚合物加工的新方法制造1-3连接材料。厚度远小于100 μ m的压电复合材料的无支撑层已经实现了小于1 μ m的表面粗糙度和陶瓷和聚合物相之间的最小不连续性。这些结果表明，超精密磨削可能在超声换能器的高频压电复合材料的实际实施中发挥作用
High frequency ultrasonic transducers are needed for high spatial resolution measurements in applications such as medical diagnosis and nondestructive testing. However, cost-effective fabrication of high performance transducers with frequencies above 20 MHz is challenging because of the need for a thin layer of active material. Piezocomposites are the material of choice in such transducers at lower frequencies, but current fabrication methods cannot easily achieve sufficiently thin active layers. Commercially, piezocomposite is usually finished to thickness by grinding, providing surface finish acceptable for most applications. However, conventional grinding is insufficiently precise for high frequency operation and is subject to undesirable intra-process variation. The most widely used alternative is precision lapping and polishing, but this is slow and therefore expensive. In the work reported here, an alternative process of ultra precision grinding was studied, using the Loadpoint PicoAce machine operating in the ductile machining mode. To determine the capabilities of this machine for piezocomposite processing, 1-3 connectivity material was fabricated using both a standard commercial process and a novel approach based on viscous polymer processing. Unsupported layers of piezocomposite of thickness much less than 100 mum have been achieved with surface roughnesses of less than 1 mun and minimal discontinuity between the ceramic and polymer phases. These results suggest that ultra precision grinding may have a role to play in practical implementation of high frequency piezocomposites for ultrasonic transducers