Development Of Bimetal Diffusion Welding Turbine Phased Array Testing Method And System

As an important power device in aero-engine system,bimetallic turbine disk needs to bear the complex cycle load and the superimposition of high temperature and high pressure and proceeds the long-term transmission of force in harsh conditions of high temperature.In order to meet the strength requirements of the new generation aircraft engine,a research institute has designed and manufactured the integrated turbine that abandoned the traditional mortise-tenon structure,and welded two high-temperature alloys with different nickel base components by vacuum diffusion welding technology.However,in the process of welding,the material may have bad bonding or even no bonding at its bonding layer.These defects will seriously affect the service performance of the turbine.Therefore,it is very important for the service performance of the new aero-engine to carry out the relevant technical research on the quality inspection of bimetallic diffusion welding turbine bonding layer.Firstly,the acoustic characteristics of two Ni-based superalloys were measured according to the structural characteristics of the bimetallic turbine disk and the connection characteristics of the diffusion welding process.Finally,ultrasonic phased array imaging was chosen to detect the bonding layer after the analysis of detection effect of multiple methods.Secondly,based on the structure characteristics of remote distance and small aperture of turbine disk,a special convex phased array probe for the workpiece was designed,the sound field of multiple convex phased arrays was simulated on CIVA simulation platform and the optimal probe parameters were determined.Thirdly,CIVA was used to simulate the defect simulation response of convex phased array.It can identify 1 mm flat-bottom holes by adjusting phase-controlled array element parameters.The convex phased array probe was made.Finally,an automatic scanning imaging system of ultrasonic phased array for turbine disk was designed and developed.The system has four DOF actions,which can be automatically detected from the hole.The distribution of defects is displayed intuitively.The results prove that,the designed ultrasonic convex phased array probe could achieve the focus of small aperture and remote distance with good focus effect.The developed automatic scanning imaging system of ultrasonic phased array can achieve the automatic detection of bimetallic turbine disk with a detection accuracy of 1mm flat-bottom hole.With strong reliability and repeatability,the system is suitable for mass production and in-service inspection of bimetallic turbine disk,and has remarkable benefit to industry.