Device evaluating thermomechanical fatigue of a material
View Patent ↗A system for cooling and holding a testpiece in an effective manner while the testpiece is subjected locally to high heat flux. The testpiece includes an inside face extended by parallel strips that leave between them channels for passing a cooling fluid, and parallel fins of an intermediate part are inserted between the strips.
1. A device for evaluating thermomechanical fatigue of a material subjected to heat flux, comprising:
a testpiece made of the material and including a hot wall with an outside face to be subjected to the heat flux and an inside face that is extended by parallel strips attached to the inside face and leaving parallel channels between one another;
an intermediate part including parallel fins shaped and dimensioned to become inserted in the channels between the strips to define a passage in a vicinity of the inside face of the hot wall for circulating cooling fluid, the passage including a plurality of parallel segments separated by the strips, a section of the passage being defined by engaging the fins in the parallel channels;
a support including the testpiece and the intermediate part installed thereon and including duct elements connected to ends of the cooling fluid circulation passage;
a cooling fluid circulation circuit connected to the duct elements; and
heater means for heating the hot wall.
2. A device according to claim 1 , wherein the testpiece includes at least one temperature sensor.
3. A device according to claim 1 , wherein outer parallel channels of the testpiece are shallower than middle channels, thereby increasing a thickness of the hot wall along its longitudinal edges.
4. A device according to claim 1 , wherein the support includes, on one face, a setback for receiving the intermediate part, in which a base of the intermediate part is received, the base carrying the fins, wherein the testpiece is fastened to the support so as to clamp the intermediate part between the testpiece and the support, and wherein the support and the testpiece are fastened to each other with a sealing gasket interposed between them that surrounds the orifices of the duct elements and the setback receiving the base.
5. A device according to claim 1 , wherein the heater means comprises a plasma torch directed towards the outside face of the hot wall.
6. A device according to claim 5 , wherein the plasma torch and the subassembly constituted by assembling together the testpiece, the intermediate part, and the support are installed in a vacuum enclosure, and wherein the plasma torch is carried by a robot arm that is controlled to adjust a position and movement of the plasma torch relative to the hot wall.
7. A device according to claim 1 , wherein the testpiece is made out of a block of material in which the parallel channels are formed.
8. A device according to claim 7 , wherein the testpiece includes at least one temperature sensor, and wherein the at least one temperature sensor is housed in a blind hole formed in a strip extending to a predetermined distance from the outside face of the hot wall together with through holes formed in the intermediate part and in the support for passing electric wires connected to the sensor.
9. A device according to claim 1 , wherein the parallel channels of the testpiece are longer than the fins of the intermediate part and extend beyond ends of the fins, the duct elements of the support leading to respective ends of the intermediate part in register with the channels of the testpiece, between ends of the channels and ends of the fins.
10. A device according to claim 9 , wherein the ends of the fins are rounded so as to correspond to a shape of the ends of the channels of the testpiece as results from the channels being milled and so as to define a plenum and guide chamber for the cooling fluid in register with each orifice of a duct element of the support.