1. Center For Precision Metrology Vibrational Finishing Process Insights Made Possible By Particle Image Velocimetry B. Mullany, E. Fleischhauer, F. Azimi, P. Tkacik, R. Keanini Department of Mechanical Engineering and Engineering Science, UNC Charlotte North Carolina, USA

2. Center For Precision Metrology Vibratory Finishing Media selection is challenging: Material: (ceramic, polymer, metal) Shapes: varied Sizes: 2 mm → 30 mm Raytech AV-75 Bowl dia. Ø 600 mm burr Process Goals: o Deburring o Isotropic finishes Other Similar Processes: o Drag o Spindle o Centrifugal o C. Barrel Tool path marks Ground surface altered by 510 mins of vib finishing SWLI 5× (1.66 mm ×1.66 mm) BeforeAfter YouTube channel search ‘UNCC’ & ‘Vibratory’ Ø 2 mm 15 mm 35 mm 10 mm 35 mm

3. Center For Precision Metrology Surprisingly High End Applications… Aerospace/ EnergyBio Medical…. plus all the usual suspects DeburringImproving the finishEnhanced surface properties Sources: all images from R ӧ sler.us

4. Center For Precision Metrology A Shortage of Diagnostics and Models In Practice o Displacement stickers o Accelerometers – vibrational freq. & amplitude Mantsunga et al.,1965 Research o Media-workpiece motion o Video imaging of the media in modified containers – particle tracking from frame to frame (Spelt et al., 2000’s and Mantsunga et al.,1965) o Tethered ‘workpieces’ containing cameras (Wang et al. 2000) o Laser displacement system (Hashenmia et al. 2013) o Workpiece- media contact forces o Stationary forces sensor (Mantunga et al 1965, Ciampini et. al 2007) o Tethered sensors (Baghbanan et al.2003, A. Yabuki 2002) o Wireless sensors (Brocker et al. 2015) (Hashenmia et al. 2013)

5. Center For Precision Metrology High Speed Camera: Redlake (Motionxtra HG-XR) Capture rate: 500 fps y x z 210 mm (b) Raytech AV-75 System Bowl dia. Ø 600 mm Operating Conditions: Motor speed: 1740 rpm Displacement: ≈ 2mm Media: Ceramic RSG 10/10 Compound: FC FLK (3% vol.) 160 mm Halogen Light: ARRI EB 400/575 D Accelerometer Could PIV provide process insights …?

6. Center For Precision Metrology High Speed Camera: Redlake (Motionxtra HG-XR) Capture rate: 500 fps 210 mm Raytech AV-75 System Bowl dia. Ø 600 mm 160 mm Halogen Light: ARRI EB 400/575 D Accelerometer Could PIV Provide Process Insights? Velocity (m/s)0.080.04 Particle Image Velocimetry (PIV) Dantec™ Dynamics Studio o 5059 image pairs o Integration area approx. 4.5 mm × 4.5 mm 0 Each velocity vector is the time averaged velocity of 5059 vectors (10.12 s) for a 20.25 mm 2 area.

7. Center For Precision Metrology PIV can Capture Process Parameters ≈ 10 s → 5090 velocity data points for each integration area FT of PIV velocity data FT of accel. data on probe Tri axial Accelerometer: PCB 356b11 Sampling 500Hz FT of accel. data End of the probe was submerged in the media (≈ 10mm) Evaluation point 5090 velocity values calculated by PIV software Accelerometer attached to slender rod

8. Center For Precision Metrology PIV Velocity Field Evaluation point PIV can Capture Media Characteristics Histogram of the velocity data as determined by PIV at the evaluation point Fourier filtering: Using the FT of the PIV data Filtering removes bulk- solid like motion of the media

9. Center For Precision Metrology PIV can Capture Media Characteristics Process Conditions: Motor Speed: 1740 rpm System Amplitude: ≈ 2mm Compound: H20+ FC FLK Media: Ceramic Based 2 mm Spherical media RSG 10/10 Char. length ≈ 10 mm ρ =2520 Kg/m 3 Mixed Media Char. length ≈ 10 mm Filtering reveals process specific information: Media Compound amplitude Dry Vib amp ≈ 2mm Dry Vib amp ≈ 6mm Wet Vib amp ≈ 2mm

10. Center For Precision Metrology Mean = 0.076 m/sMean = 0.066 m/sMean = 0.042 m/s Mean = 0.061 m/s Mean = 0.06 m/s Prelim Data on Other Media Types Plastic 10 mm, 8 mm ρ= 1820 kg/m 3 Ceramic 10 mm, 10 mm ρ= 2520 kg/m 3 HD Ceramic 9 mm, 9 mm ρ= 3600 kg/m 3 Ceramic 10 mm, 22 mm ρ= 2520 kg/m 3 Ceramic 19 mm ρ= 2520 kg/m 3 Counts Velocity, m/s m/s

11. Center For Precision Metrology Upstream Downstream U4U3U2 D1D2D3 Upstream Downstream Light Camera Steel rod Vibratory bowl Test piece Steel rod Vibratory bowl Media Camera’s field of view Media flow around stationary Parts Ground stainless- steel workpiece: (≈75mm ×100 mm ) SWLI 5× Sq = 0.37  m 1.66 mm

12. Center For Precision Metrology Upstream Downstream U4U3U2 D1D2D3 Upstream Downstream Light Camera Steel rod Vibratory bowl Test piece Steel rod Vibratory bowl Media Camera’s field of view Media Flow around Stationary Parts 0 0.082m/s Downstream Ground stainless- steel workpiece: (≈75mm ×100 mm ) SWLI 5× Sq = 0.37  m 1.66 mm

13. Center For Precision Metrology Downstream Camera Vibratory bowl Media flow around Stationary Parts Ground stainless- steel workpiece: (≈75mm ×100 mm ) SWLI 5× Sq = 0.37  m SWLI 5× Sq = 0.43  m Down stream Workpiece U4U3 D1D2 Steel rod Workpiece Direction of the 5029 |Velocity| 2 Vectors ° deg Vel 2 SWLI 5× Sq = 0.32  m Up stream

14. Center For Precision Metrology Going Forward … Ultimate Goal = Predictive Model o Uniformity of finish o Finish quality o Mrrs Current Research Focus o CFD Modeling o Media ‘Viscosity’ determination o Better understanding of surface finish evolution o … Questions or Comments?