Keith Legg Plasma spray ID coatings HCAT Program Review August 2001 Toronto

Keith Legg Summary of technology development approach

Keith Legg The story so far All coatings made in 3” ID tubes 3 guns used  Praxair 2700 (1.5” min)  SM F100, F210  perhaps look at new SM F300 miniature gun Evaluated large number of WC materials to find those with lowest porosity Designed common coupon coating rig Measured particle T and V for guns and powders so can determine process windows and transfer processes Begun to develop uniform porosity measurement procedure In midst of optimization preparatory to making test coupons

Keith Legg Materials to be optimized Tribaloy 400  softer, lubricious, low porosity Diamalloy 2003, or equivalent, fused and crushed WC- Co  lowest WC-Co porosity  evaluate standard and small particles Diamalloy 2002, or similar, 75(WC-12Co) NiCrFeSiBC self -fluxing blend  softer than WC-Co but low porosity  evaluate alloy modifications

Keith Legg Tribaloy development - Praxair, NRC Small particles allow higher T, probably also higher V But small particles (600 mesh, 20 µm) too difficult to feed reliably  trials continuing with 400 mesh, 38µm powder), which feeds much more readily  smooth, low porosity  decent coatings at 1.5” standoff (approx 2” ID) with 38µm powder T-800 T-400 fine 2005 NS

Keith Legg T 400 microstructure Porosity 6%  measurement depends on met prep  best porosity method appears to be vacuum infiltration Hardness ~ HV  softer than carbides  lubricious - can be used against itself (piston + ID)  becoming used in some actuators Almen can = 0 (no residual stress)  very important for fatigue  most plasma spray coatings are tensile

Keith Legg Diamalloy 2003 Fused WC-12Co Porosity 4%  close to requirements, may need sealing Microhardness 780 HV 300  lower than standard OD coatings, but certainly adequate Likely to be more brittle than WC-17Co  may not matter too much in IDs Cross section, 200X

Keith Legg Diamalloy 2002 WC-12Co self-fluxing with NiCrFeSiB Porosity <1% Microhardness 670 HV 300  lower than WC-12Co but acceptable Expected to be more lubricious and less brittle than WC-Co  may be ideal combination of wear resistance, lubricity, porosity, toughness  blend - can adjust blend for optimum combination of wear and lubricity May be good for ODs too Cross section, 200X

Keith Legg Sample holder - 3”ID Coat coupons for all tests under ID conditions  metallography  adhesion  wear  corrosion  fatigue

Keith Legg To be done Standard coupon jig being made for NRC, Sulzer Metco, Praxair  to ensure samples produced under equivalent conditions Optimize coating parameters  spray coupons for testing (fatigue, corrosion, etc) Perfect methods for temperature and particle control Porosity measurements to be normalized and all final measurements to be made at NRC S-M may evaluate new F-300 miniature gun Determine minimum sprayable ID  determines range of applications