STRENGTH AND MODULUS OF A MOLYBDENUM-COATED TI-25AL-10NB-3V-1MO INTERMETALLIC

The three-point bend strength, Young's modulus, and vibrational dampin g of a plasma-sprayed molybdenum-coated Ti-25Al-10Nb-3V-1Mo intermetal lic were measured, The bend strength of the intermetallic samples was significantly reduced as a result of the molybdenum coating, This decr ease in the strength was attributed to cracks formed in the molybdenum coating during the plasma spraying process, Experimental measurements done using the piezoelectric ultrasonic composite technique (PUCOT) i ndicated that the modulus and vibrational damping of the coated sample s were significantly higher than for the uncoated substrates, Thermal cycling of the molybdenum-coated intermetallic between 600 degrees C a nd room temperature revealed a saturation increase in the modulus with a corresponding decrease in the mechanical damping, This behavior was attributed to crack healing occurring in the molybdenum coating durin g the thermal cycling process.