Creep and stress rupture testing of high-performance material at elevated temperatures provides important details used in the design of components for the aerospace industry. A
creep test subjects a material to a constant load at a constant temperature with deformation as a function of time being measured.
Stress rupture testing subjects the material to a constant load at a constant temperature with the time to rupture being measured. Our specification required us to determine creep and stress rupture data to be used to predict the rate of growth of turbine blades.
For the stress rupture test, we chose the Model M3 Lever Arm Creep / Stress Rupture Tester. We included the Model SF16 split furnace for applications of temperatures up to 2000° F for operation on a 120V, 1 Phase, 50/60HZ, 30 amp circuit. Our 380 lb Class F serialized and certified load weight set is used to develop the maximum capacity of 6,000 lbs through the 16:1 lever arm ratio (i.e.: 20 lb weight produces 320 lbs at the load train). High-temperature components required to complete the load train include (2) pull rods and (2) threaded holders. We suggest the use of additional equipment to determine creep properties.
Our high-temperature extensometer and replaceable inserts are used to contact the specimen in the elevated temperature environment. Our choice of LVDT provides for specimen elongation measurement up to 0.100 inches with attachment to the end of the extensometer. This LVDT signal is conditioned for an output signal of 0 - 50 mV through the use of our AK-1 Module. The use of multiple machines set up for either creep or stress rupture procedures permit the variable load and temperature applications of selected material for use in the design of the component.
Creep and stress rupture data of high-performance material provides data to determine the useable life of a turbine blade. We can predict the rate of growth of turbine blades so that the blades can be replaced before contacting the engine housing. This data can be used to develop maintenance schedules that require turbine blades to be replaced after a certain number of service hours.