Research Of Superalloy Turbine Disk By Phased Array Testing System

Nowadays,aircraft engine turbine disc mainly adopts high temperature alloymaterial, because its coarse grains, microscopic structure is complex, low signal tonoise ratio, nondestructive testing effect is not ideal, small size of defects is difficultto identify, even1mm defects can be hard to gauge. Coarse grain materials,therefore, small and medium-sized defects effective identification methods becomean urgent need to solve the problem.This article first embarks from the existing detection methods, compare andanalysis the pros and cons of a variety of detection means, selection of focusingultrasonic phased array inspection as this topic detection method, by adopting themethod of the annular phased array with time reversal technology of test scheme,and core ideas detection system design.Ultrasonic testing system, the performance of the sensor and the hardwarecircuit system has decisive effect detection sensitivity and resolution. The author isfrom the two aspects to carry on the design.First, the axial with excellent design in sound field is focused on theperformance of the annular phased array probe, the ring array size, chip materialeffect on the focusing characteristics.Second, design the hardware system, according to the maximum extent toreduce electrical noise’s influence on the system principle of design of PCB.At the same time, in line with high performance, low power consumption,miniaturization and upgrade potential design aim, system of using high-densityintegration of IC and electronic design automation tools. Use special high pressurepulse generating chip MAX4940inspire of up to200V, the edge of a steep squarewave voltage, using industrial PC and ARM7to control the whole system, usingCPLD to realize high precision phase delay trigger, using the FPGA to realizereceiving circuit large amount of data processing functions, and will collect datathrough the PCI bus real-time transmission to industrial. And starting from the actualneeds, writing μC/OSⅡ system on ARM7chip control software and industrial PCcontrol software based on Labview.Finally for the phased delay part of the system has been optimized, making thesystem run stability in the frequency of250MHZ, achieved4ns precision phasecontrol function.