毕业论文（设计）激光快速成型TC4射线衰减系数测量.doc

激光快速成型TC4射线衰减系数测量
摘要:TC4钛合金属于α+β型钛合金,该合金因为强度高,耐腐蚀性好,热稳定性好等优点,被广泛应用于各个领域工业中,如汽车工业、体育和医学等民用领域也有应用。在激光快速成型TC4合金中,利用平板探测器发出X射线透照工件,测量其衰减系数。工件衰减系数与众多因数有关,只有了解衰减系数的变化规律才能有效地控制各参数对工件性能测量。而透照电压是引起衰减系数变化的主要原因。因此,怎样更好的选择透照电压是工件性能测量的关键。
本文采用DR平板探测器对激光快速成型TC4钛合金的衰减系数进行测量,在不同电压下进行射线透照,每个电压中分别选取两个不同的曝光量下的曝光底片用作衰减系数的测量。曝光底片要求为包含灰度22000,即最厚处灰度小于22000最薄处高于22000即可,但最大灰度不能高于65535,避免其过度曝光。运用imageJ和origin8软件绘制不同电压下绘制灰度与厚度拟合曲线,通过拟合曲线得到灰度22000对应的厚度,再根据公式计算得出衰减系数的大小,最后分析实验结论利用origin8软件绘制衰减系数与电压关系图像,得到最终处理结果。
关键词: 激光快速成型衰减系数 DR平板探测器灰度

指导老师签名:
Rapid Prototyping TC4 Ray Attenuation Coefficient Measurement
Student name:li Jiangchuan Class:110813
Supervisor: Zhang Shijing
Abstract: Alpha + beta type titanium alloy TC4 titanium alloy belongs to, the alloys with high specific strength, good corrosion resistance, good thermal stability and advantages, is widely used in the aerospace industry and so on, in addition to the automobile industry, sports and medical and other civilian areas can also be used. In rapid prototyping TC4 Alloy, the use of flat panel detectors emit X-ray radiographic artifacts, Measuring the attenuation coefficient. Workpiece and many factors related to the attenuation coefficient, only by understanding the variation of the attenuation coefficient in order to control the parameters of effective performance measurement of the workpiece. The radiographic voltage is the main cause of attenuation coefficient variation. So, how better choice is a key piece in the voltage through performance measurement.
In this paper, DR flat panel detector for rapid prototyping laser attenuation coefficient is measured TC4 titanium alloy. At different voltages radiographic, each voltage select negatives were exposed to two different exposure measurements used under the attenuation coefficient. Exposure negatives requirements to include gray 22000, that is less than 22,000 gray thick at the thinnest point higher than 22000 can be, but not higher than the maximum gray 65535, avoid ov