Research On The Automatic Testing System For Weak Magnetic Field Of Titanium Alloy Plate

Titanium is widely used in aerospace,nuclear industry,shipbuilding,medical industry and other industries because of its excellent comprehensive performance.At present,the main production of titanium in our country is plate,and the defects of micro crack and folding are easily produced in the process of production and processing.The mechanical properties of titanium plate are greatly reduced.When it is serious,the plate fracture and a large number of titanium alloy parts will be discarded.Therefore,the quality requirements of the titanium plate are becoming higher and higher in industry.At present,the conventional nondestructive testing method is not suitable for the industrial production of titanium alloy sheets.In this paper,a weak magnetic detection method is proposed to develop an automatic detection system for detecting micro crack defects of the material on the surface of titanium alloy plate.In this paper,Deriving from the basis of the theory of weak magnetic detection,the source of material magnetism is analyzed.The magnetization curve of titanium alloy is obtained.It is proved that the titanium alloy is paramagnetic material.The effect of different defect size,lift height,defect inclination angle and defect distance on weak magnetic detection ability is analyzed and analyzed.The feasibility and reliability of weak magnetic detection on titanium alloy surface micro crack defect are proved by using prefabricated artificial defects.Secondly,According to the defect detection requirements in the industrial production process of titanium alloy plate,developed a set of weak magnetic automatic detection system The system consists of array-type magnetic sensor,transmission system,mechanical sliding table and host computer software.The hardware part mainly included array-type magnetic sensors,transmission systems,and mechanical slides.The software part mainly included the precise control of the stepper motor,the design of the host computer software interface,data processing and defect two-dimensional imaging.Finally,combined the hardware part and the software part to from a complete set of magnetic flux weakening automatic detection system for titanium alloy plate.According to the feature of weak magnetic detection signal,wavelet threshold de noising method is selected,and threshold and decomposition level for weak magnetic detection signal are summed up.According to the method of mathematical statistics,a weak magnetic detection defect recognition algorithm is designed,and the spline interpolation is used to interpolate and interpolate the data points collected by the 12 sensors,and the two-dimensional imaging of the defect is realized.