数字射线检测影像评价参数与透照参数的关系研究  

Study on Relationship Between Evaluation Parameters of Digital Radiography Image and Exposure Parameters

作　　者：谢缙云 张尤 高鸿波[1] 王树鹏 杜本莉 邬冠华[1] 满龙 XIE Jin-yun;ZHANG You;GAO Hong-bo;WANG Shu-peng;DU Ben-li;WU Guan-hua;MAN Long(Key Laboratory of Nondestructive Testing(Ministry of Education),Nanchang Hangkong University,Nanchang 330063,China;AECC Shenyang Liming Aero-Engine Co.,Ltd.,Shenyang 110043,China;Tianjin Aerospace Long March Rocket Manufacturing Co.,Ltd.,Tianjin 300462,China)

机构地区：[1]无损检测技术教育部重点实验室(南昌航空大学),南昌330063 [2]中国航发沈阳黎明航空发动机有限责任公司,沈阳110043 [3]天津航天长征火箭制造有限公司,天津300462

出　　处：《失效分析与预防》2021年第3期191-196,共6页Failure Analysis and Prevention

基　　金：无损检测技术教育部重点实验室开放基金(EW201908088)。

摘　　要：以TC4钛合金试样为研究对象,对数字射线检测透照参数(曝光量、放大倍数、焦距)与图像信噪比及空间分辨率的关系进行研究。结果表明:在透照管电压为90 kV的条件下,当管电流在2.0~8.5 mA范围内,钛合金DR图像空间分辨率随着曝光量的增加无明显关系,DR图像信噪比随曝光量的增加而增大。当固定管电流为7 mA,放大倍数从1.0增加到5.0,DR检测图像空间分辨率与放大倍数呈正相关,而信噪比在放大倍数1.0~3.5倍之间呈现急剧增大后缓慢增加现象,放大倍数大于3.5倍后,信噪比趋于恒定值。保持放大倍数为2,源到探测器距离在100~180 cm范围内变化时,钛合金DR检测图像空间分辨率和图像信噪比均与源到探测器距离呈正相关。综合分析可知,在一定范围内,选择较高的曝光量、较大的源与探测器距离及合适的放大倍数,TC4钛合金图像空间分辨率和信噪比达到较高水平,提高系统缺陷检出能力。Taking TC4 titanium alloy specimens as research objects,the relationship between digital radiographic parameters(exposure,magnification,distance from X-ray Source to the flat panel detector)and signal-to-noise ratio(SNR)and spatial resolution of DR image was studied.The experimental results show that the SNR of DR image increases with enhanced exposure while no significant correlation is observable between spatial resolution and exposure(Tube voltage:90 kV;Tube current:2.0~8.5 mA).When the tube current is fixed at 7 mA and the magnification is increased from 1.0 to 5.0,the spatial resolution is directly proportional to the magnification,while SNR presents a trend that first increases sharply and then strengthens slowly within the magnification range from 1.0 to 3.5.Until the magnification is higher than 3.5,SNR tends to be constant.When the magnification is maintained at 2 both the image spatial resolution and SNR are directly proportional to the distance(100~180 cm)from the source to the detector.Taken as a whole,high image spatial resolution and SNR of TC4 titanium alloy can be obtained by setting suitable parameters including high exposure,large distance from the X-ray source to the flat detector,and appropriate magnification.

关 键 词：数字射线检测 信噪比 空间分辨率 透照参量 

分 类 号：TG115.28[金属学及工艺—物理冶金]