The Nondestructive Research On The Alloy Phase Transformation Prediction Based On Femtosecond Laser-induced Breakdown Spectroscopy

The phase constitution of the material is an important foundation and basis to the material service performance and processing application.However,whose identification need the high cost,labor and time wasting and material damage preparation,including material cutting,mounting and grinding,which greatly block the development and progress in the material science.However,The testing technology of femtosecond laser-induced breakdown spectroscopy(fs-LIBS)has been widely used in the field of material,archaeology and biology for its merits,including cold processing,low cost,high speed and without sample damage.So,One novel quick phase constitution testing method based on laser induced plasma spectroscopy is put forward in this article,in which researching the qualitative relationship between the spectral parameters and phase constitution under the varied laser energy density,analysing and demonstrating the mechanism of the influence of different energy density and phase constitution on the plasma spectroscopy,whose researching object and method is the binary alloy and vaired laser energy density.The concrete content in this article is as follows:1.Building the spectral collecting system during the femtosecond laser ablation based on the femtosecond laser material processing feature.Meanwhile,pre-processing the collected original spectrum could obtain the high precision and accuracy subsequent analysing spectrum with high signal-background and signal-noise ratio.2.Obtaining the characteristic line intensity ratio from the pre-processed spectral,the qualitative relation among the line intensity ratio,atomic percentage and phase constitution could be built under the single energy density.The result shows that the trend of calibration curve built between the line intensity ratio and the atomic percentage would change for the alloy with the vaired phase constitution,but such trend would be stable for the alloy with the unchanged phase constitution.3.The qualitative relation is built between the calibration curve and the phase constitution under the varied energy density.The results shows that the trend of the calibration curve in the low energy density are the same as that in the single energy density,but the changed trend disappear for the alloy with the varied phase constitution when the input energy density is increased to one value,and the linearitytrend of calibration curve is not changed for the alloy with the unchanged phase constitution.4.The results of the calibration curve mention above is theoretically explained as that the phase potential difference causing the phase stability difference,then leading to the composition deviation when the different phase target ablated by the femotosecond laser,resulting in the changed trend of the calibration curve.Combining the experiment result,in which the composition deviation from the internal ablation area to the external ablation area under the low and high energy density ablating the phase changed and unchanged alloy,to systematically explain the calibration curve trend.The results shows that it is the phase potential difference that inducing the changed trend of the calibration curve,so the trend of the calibration curve changed or not could be used as predicting the phase constitution varied or not.