High Throughput Characterization Of Microstructure And Mechanical Properties Of Ti-Al-V Titanium Alloys Produced By Laser Solid Forming

The characteristics of laser solid forming technology,such as small melting pool and point by point preparation,make the technology has great application potential in high-throughput preparation.Its powder feeding characteristics make the technology itself an advanced material high-throughput preparation technology.In order to speed up the research and development of special alloys in laser solid forming material system,the most common Ti-Al-V biphasic titanium alloys in aerospace are taken as the research object in this study.Combined with the high-throughput characterization and performance prediction of microstructure,the database of composition-microstructure-mechanical property relationship of Ti-Al-V alloys in laser solid forming is preliminarily established.The main conclusions are as follows:(1)Using Ti,Al and V metal powders as raw materials,Ti-xAl-yV(0<x<8;0<y<15,wt.%)alloys samples with different compositions were prepared rapidly by laser solid technology.The process is systematic,consistent and uniform,which shows that laser solid forming technology,can be used as a high-throughput preparation technology to complete the high-throughput preparation process of materials.(2)The microstructure of Ti-Al-V alloys is effectively classified and identified based on the principle of image informatics,and the features of its intragranular microstructure were extracted and characterized by high-throughput computer-aided macro programming language.The results showed that when the contents of Al and V elements are 0<x<8 and 0<y<15,wt.%,the width of ?-lath is in the range of 0.3?0.9 ?m,and the volume fraction of ?-phase is mainly in the range of 65 %?75 %.(3)The microhardness,elastic modulus and yield stress of Ti-xAl-yV(0<x<8;0<y<15,wt.%)alloys were obtained by high throughput using microhardness and prediction model of material mechanical properties based on micro indentation reverse algorithm.The results showed that as the contents of Al and V elements varied in 0<x<8 and 0<y<15,wt.%,the microhardness distribution droped in the range of 200?550 HV,and the microhardness shows a high linear fitting trend with the content of Al and V elements.The error between the prediction results of yield strengthbased on micro indentation reverse algorithm and the room temperature tensile results is less than 5 %,which shows that the micro indentation process can be used as a high-throughput characterization method of material mechanical properties.(4)Based on MATLAB software,a BP neural network model for predicting the composition,microstructure and properties of Ti-Al-V alloys in laser solid forming is established,which can process and analyze data quickly by computer.The results show that the average error of the width of the ?lath is 1.587 %,the average error of the volume fraction of ? phase is 2.488 %,and the average error of the microhardness output value and the measured value is 3.268 %,which shows that the BP neural network model of composition-microstructuremicrohardness established in this study has good accuracy.