【摘要】 利用超声技术研究了辨识金属材料的方法.以成分相近、热处理温度相同和成分相同但热处理温度不同的多个金属材料为例,计算了金属材料对不同频率超声波的衰减系数,分析了同一频率下采样率对超声衰减谱稳定性的影响,研究了金属材料的微观组织对超声衰减的影响.结果表明,采样率越高,衰减谱的多次实验计算越趋于稳定;金属材料的超声衰减谱与其微观组织结构密切相关,其携带有金属材料的微观组织特征信息;利用金属间超声衰减谱相关系数可辨识金属材料,对贵重金属、金属文物等的防伪与辨识提供了一定的参考依据.更多还原

【Abstract】 Metallic materials are widely used in aerospace, medical, nuclear energy, mechanical manufacturing and other critical areas. For security applications, it needs to use qualified metallic materials. Therefore, it requires an extremely high resolution security identification technology. In addition, there needs to be an identification of the precious metallic cultural relics and metallic materials used in military equipment. Firstly, the effects of sampling rate on the stability of attenuation spectrum are discussed at the same frequency, and the effects of microstructure characteristics of metal materials on ultrasonic attenuation coefficient also are studied. Tests and calculations show that the more stable ultrasonic attenuation spectrums can be obtained at the higher sampling rates. Secondly, a new method to identify metallic materials using ultrasonic technology is developed in this paper. Taking some metallic materials with similar ingredients at the same heat treatment temperature and some of the other metallic materials with the same ingredients but at different heat treatment temperature for examples, the method for identification of metallic material based on the calculation of correlation coefficient of the attenuation spectrums between two metallic materials is investigated. The results show that the correlation coefficient of the attenuation spectrums in between of the same metallic materials is greater than that of in between of different ones. As a result, a conclusion can be drawn that the correlation coefficient of ultrasonic attenuation spectrums is applicable for identification of metallic materials. Compared with the conventionally physical and chemical identification methods, the proposed method for identification of metallic materials in this paper is nondestructive, accurate, rapid, and pollution-free.更多还原