Creep Suplement.ppt

constant strain rate constant stress (creep) Deformation tests ( constant T ) Constant strain rate testing + Extensometer INSTRON 2630-014 (g.l. 10 mm, range 50 %) At our lab: Electromechanical (Instron 1123 or 5567) Universal Electromechanical Testing Machine Instron 5567 (dual column table top, 30 kN) Temperature Chamber Instron 3119 (-70 °C / 250 °C ) Servohydraulic Testing Machines (MTS 810) Constant strain rate behaviour ... details at T = 573 K (Th 0.6 ! For the Al-alloy) … why not constant loading-rate experiment? Creep Testing: top-lever machine P P P 10 mm initial state after creep Compression Test Compression Cage Creep behaviour The Monkman-Grant Relationship for time to fracture : time to fracture : minimum creep rate or, more general: where: 0.77m0.93; 0.48BMG1.3 for Al, Cu, Ti, Fe and Ni base alloys (from Monkman-Grant research) Test of Monkman-Grant for Cu Engineering Estimates of Creep Behaviour Larson-Miller parameter (LM) ksi ksi Fig a * * * * * * * * * * * * * * * *