LA103Z镁锂合金锻件超声评价技术

Ultrasonic evaluation technique of forging for magnesium-lithium alloy LA103Z

针对镁锂合金锻件检测时存在超声波能量的严重衰减,导致无法实施有效的内部质量检测难题,通过对不同锻造变形量下的LA103Z镁锂合金锻件进行金相观察,分析了不同变形量对材料微观结构造成的影响;同时还分析了不同变形量对超声波衰减系数及材料纵波声速的影响,最后研究了探头晶片尺寸对超声波衰减系数的影响。结果发现,对于LA103Z镁锂合金锻件,锻造变形量越大,镁锂合金α相微观组织越细密;超声衰减系数随锻造变形量增大而减小;材料的超声波纵波声速随锻造变形量增大而增大;随着超声检测探头晶片尺寸增大,超声波衰减系数减小;相同变形量的镁铝合金材料,随着使用的探头频率的提高,材料的声波衰减系数和声速都变大。

For the difficulty of effective internal quality inspection caused by a serious attenuation of ultrasonic energy in the testing of magnesium-lithium alloy forgings,the magnesium-lithium alloy LA103 Z forgings under different forging deformations were studied by metallographic observation,and the influences of different deformations on microstructure were analyzed. Then,the influences of different deformations on ultrasonic attenuation coefficient and longitudinal wave velocity of material were analyzed,and the influence of probe wafer size on ultrasonic attenuation coefficient was also studied. The results show that the greater the forging deformation of magnesium-lithium alloy LA103 Z forging is,the more dense microstructure of α-phase magnesium-lithium alloy is. Furthermore,the ultrasonic attenuation coefficient decreases with the increasing of forging deformation,and the ultrasonic longitudinal wave velocity of material increases with the increasing of forging deformation. However,the ultrasonic attenuation coefficient decreases with the increasing of ultrasonic probe wafer size. Thus,with the enhancement of probe frequency,the acoustic attenuation coefficient and the sound velocity of material become larger for magnesium-lithium alloy under the same deformation.