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本文叙述了空军材料实验室(AFML)在关于检测块状石墨及碳/碳复合材料微缺陷方面所进行的工作,提出了一些优良的射线照相法。用对比液体如四溴乙烷(TBE)浸泡,使影象质量及灵敏度有显著的改进,能分辩石墨中的微孔结构和微裂纹,并可提供较清晰的复合材料的编织型式。如果将试件埋置在已知射线照相均匀性和原子序数相近的材料中,当测定厚度有变化的部件(如鼻锥、喷管等)时,将有助于射线照相法。埋置方法使出现在相近厚度范围内的缺陷,具有更均匀的厚度。以便提高检测能力。摄影接触印相机与对比度大的感光乳剂配合在一起,可为检测微缺陷提供更多的信息。
This article describes the Air Force Materials Laboratory (AFML) work on micro-defects in the detection of bulk graphite and carbon / carbon composites and offers some excellent radiographic methods. Soaking in a contrasting liquid such as tetrabromoethane (TBE) markedly improves image quality and sensitivity, distinguishes micropores and microcracks in graphite, and provides clearer patterns of weaving of composites. If the specimen is embedded in a material that is known to have similar radiographic uniformity and atomic number, radiographic methods are useful when determining the variation in thickness (eg, nose cone, nozzle, etc.). Burial methods make defects appear in similar thickness range with more uniform thickness. In order to improve the detection ability. Photographic contact printing cameras and large contrast emulsions together, can provide more information for the detection of micro-defects.