Turbo Power Life Prediction- Overview Company, Department, Name day month year

VAC specialisation components Compressor structures VAC develops and manufactures parts to aero engines The manufacturing idea ↔ “Make it Light” : Fabricated structures i.e. total structure manufactured from sub-components (cast, sheet, forged material quality) Typical fabricated components Frames for: ”Cold” parts, Material:Titanium Temperatures < 450 °C Hot parts, super alloys (nickel base materials) temperatures < 550 °C New manufacturing processes Metal Deposition (MD) Fabricated structures  welds  defects (cracks) Turbo Power focus on hot parts Turbine structures ”Hot” ”Cold” Slide 2 Turbo Power

Fabricated structures Welding issues from a manufacturing point of view: Effects of deformation Residual stress distribution Temperature distribution Fixturing Weld sequence Welding issues from a design point of view: Initial defect sizes Material properties in welds Weld geometry Calculation models Residual stress distribution Slide 3 Turbo Power

Titanium & Ni-based structures Metal Deposition, MD Titanium & Ni-based structures What is MD? Building 3-D geometries directly in metal using a welding source and filler material Why MD? For aero engine components enable Shorter lead time for product development Cost effective fabrications - replace one-piece castings New repair procedures Mechanical properties  cast + HIP Cost effective MD process by automation Process Knowledge CAD model Generate weld paths Simulation On-line controlled process MD’ed geometry Control Weld prep / flange Boss Slide 4 Turbo Power

How does Fatigue life methods relate to NDT inspection ? Cast material and welded structures are more likely to have inherent defects in the structure (2c~0.1 to 1.5 mm) than forged or sheet material. NDT-inspection on finished part  risk of missing defects  one must allow defects in the structure Conclusion: Crack initiation analysis: Neglecting risk of cracks in structure  un-conservative LCF life prediction Crack propagation analysis: Defining initial defect size from NDT (2c~1.5 mm)  risk of very conservative life prediction Δ ε Cycles to ”initiate” a crack in a structure structure Ni Stress Stress Temperature Cycles to propagate a crack until failure weld Time Slide 5 Turbo Power

Summary Fatigue is a very complex phenomenon! A successfull fatigue analysis procedure involves: Material science/testing Mathematical modelling Manufacturing methods Quality control Slide 6 Turbo Power

Overview of projects Fatigue life of thermal barrier coatings (TBCs) physically based modelling Project aims at evaluate existing life methods for Thermal Barrier Coatings on Heynes 230, Hast-X and turbine material (no single crystal material). Experiments and model evaluation at LiTH VAC supplies test specimens, experiments and expertise SIT supplies support on numerical simulation of experiments and expertise and perform limited amount of experiments Funding: 3300 kkr Quantification of the reliability of flaw detection for non-destructive techniques using probability of detection (POD) based on synthetic data The main objective of this project is to enable simulated data to be used within the development of POD curves. These POD curves can then be used to find the optimal NDT technique in aspect of a specific object, material, defect size and other defect characteristics Chalmers: Modeling and evaluation VAC: Supplies expertise within NDT area Funding: 2450 kkr High temperature fatigue life prediction Project aims at developing life models for the combination of cyclic loads and time dependent damage (Crack Initiation and Crack Propagation). Material, IN718. Experiments and model development at LiTH VAC supplies test specimens and expertise SIT supplies experiment and expertise Funding: 3770 kkr Slide 7 Turbo Power