STANDING WAVE PROBES FOR DIMENSIONAL METROLOGY OF LOW DENSITY FOAMS

Seugling, R M ; Woody, S C ; Bauza, M B

关键词: ASPECT RATIO;    AUTOMOTIVE INDUSTRY;    CERAMICS;    COPPER;    DIELECTRIC MATERIALS;    FABRICATION;    GEOMETRY;    INTERFEROMETRY;    LAWRENCE LIVERMORE NATIONAL LABORATORY;    MICROSCOPY;    PHYSICS;    PLASTICS;    PROBES;    RADIATION TRANSPORT;    RESOLUTION;    STANDING WAVE;   

DOI  :  10.2172/975224
RP-ID  :  LLNL-TR-426347
PID  :  OSTI ID: 975224
Others  :  TRN: US201009%%432

学科分类：工程和技术（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Typically, parts and geometries of interest to LLNL are made from a combination of complex geometries and a wide array of different materials ranging from metals and ceramics to low density foams and plastic foils. These parts are combined to develop physics experiments for studying material properties, equation of state (EOS) and radiation transport. Understanding the dimensional uncertainty of the parts contained within an experiment is critical to the physical understanding of the phenomena being observed and represents the motivation for developing probe metrology capability that can address LLNL's unique problems. Standing wave probes were developed for measuring high aspect ratio, micrometer scaled features with nanometer resolution. Originally conceived of for the use in the automotive industry for characterizing fuel injector bores and similar geometries, this concept was investigated and improved for use on geometries and materials important to LLNL needs within target fabrication. As part of the original project, detailed understanding of the probe dynamics and interactions with the surface of the sample was investigated. In addition, the upgraded system was utilized for measuring fuel injector bores and micro-lenses as a means of demonstrating capability. This report discusses the use of the standing wave probe for measuring features in low density foams, 55 mg/cc SiO{sub 2} and 982 mg/cc (%6 relative density) copper foam respectively. These two foam materials represent a difficult metrology challenge because of their material properties and surface topography. Traditional non-contact metrology systems such as normal incident interferometry and/or confocal microscopy have difficulty obtaining a signal from the relatively absorptive characteristics of these materials. In addition to the foam samples, a solid copper and plastic (Rexolite{trademark}) sample of similar geometry was measured with the standing wave probe as a reference for both conductive and dielectric materials.