航空用热收缩防护材料的超声评价

Ultrasonic evaluation of heat-shrinkable material in aviation area

航空用热收缩防护材料是一种新型的功能高分子材料,应用越来越广泛。针对含有自然缺陷的热收缩材料试样,采用超声检测方法开展了该材料中的声速、声衰减测试试验以及典型缺陷的评价试验,并对缺陷区域进行了解剖及金相组织分析。试验结果表明:采用超声方法可对该材料进行检测,但缺陷可检性受材料厚度、形状和声衰减系数等条件制约;不同体系的热收缩防护材料的声衰减程度不同,含氟体系声衰减最大,改性烯烃体系声衰减居中,改性弹性体材料体系声衰减最小;材料中的宏观缺陷和微观孔隙均可通过超声技术得到有效评估。

Heat-shrinkable material for aviation is a new kind of functional polymer material,which has been widely used recently.In this paper,ultrasonic testing was used to characterize the specimens of heat-shrinkable materials with natural defects.Sound velocity and amplitude attenuation of the material were used for flaw characterization in two scales.The defect zone was also dissected and analyzed based on metallography result.The results indicated that the ultrasonic method could effectively characterize the heat-shrinkable material,but its capability in defect detecting was restricted by the thickness,shape and sound attenuation of the material.Besides,the amplitude attenuation for different heat-shrinkable material is quite different.The amplitude attenuation coefficient for the material containing fluorine is the largest,and becomes smaller for the modified olefin material.It is the lowest for the materials with modified elastomer.Moreover,both defects in macro scale and micro scale in the material can be effectively evaluated by the ultrasonic testing.