Research On Phased Array Inspection Technology Of Double Metal Composite Materials In Coal Preparation Plant

In recent years double metal composite material is widely used to crushers,ball grinding mills,magnetic separators,press filters,flotation cells and other equipments in coal preparation plant due to its good use performance about steady size,high strength,strong wear resistance,fatigue resistance and corrosion resistance.Double metal composite material not only saves a large number of rare resources,but also reduces the equipment cost.Directing at the problem that double metal composite material can easily produce interface and surface defects during the process of production and use,this paper selects the ultrasonic phased array technology to check defects in double metal composite plate.The main research content is as follows:(1)The development situation about ultrasonic phased array inspection technology at home and abroad was introduced.And this paper expounded the basic principle of ultrasonic phased array inspection technology and related core technology,including the emitting-receiving of ultrasonic phased array,beam control.On this basis,the paper deduced calculation formula of each element delay time about deflection,focus and deflection-focus.(2)The paper studied sound field of one-dimensional linear array probe,established phased array probe beam directivity model of single rectangular array element and multiple rectangular array elements.Then phased array probe radiation sound field is separately established in the single medium and double medium.Finally the paper used Matlab to simulate the influence of element number,center distance,element width and center frequency on sound field distribution and beam directivity,which provided gist for choosing the appropriate ultrasonic phased array probe to detect double metal composite board.(3)Automatic scanning system of phased array probe was designed and its walking mechanism,control circuit,software programming,probe fixture and holder were respectively analyzed and designed in detail.The paper designed X-Y axial guideway module which consists of three synchronous belt type linear slider,analyzed stepper motors,drives,controller,MCU and other main part of automatic scanning system and illustrated the running process of the system in detail.(4)The paper used test system to carry ultrasonic phased array testing experiment on carbon steel-stainless steel composite plate.Manual and automatic scanning system are used to detect horizontal holes,corrosion pit and flat bottom hole defects in specimen.Through contrast and analysis of test results,it is found that defect error rate can be reduced by more than 10%when using the automatic scanning system.And the effect of automatic scanning system is verified.