Furnace for testing materials and characterization method using the furnace

Abstract

A furnace comprising both overall heating means and local heating means for generating both an ambient temperature and local heating of the specimen so as to be able to simulate a mechanical shock. It therefore lends itself to various tests capable of providing a better evaluation of the self-heating or self-ignition characteristics of a material subjected to a thermal or mechanical stress.

1 . Furnace for testing materials, comprising an enclosure, a tray for receiving specimens of materials at an upper surface, and a first adjustable heating means, which is overall and spread around at least one part of the enclosure, characterised in that it further comprises a second adjustable heating means, which is of defined geometry, passing through the upper surface of the tray and extending up into a place for receiving a specimen. 
     
     
         2 . Furnace for testing materials according to  claim 1 , characterised in that the tray forms part of the enclosure, which is also composed of a bell laid on the tray and which can be separated from the tray, the first overall heating means are spread out on the tray and around a lower part of the bell, and the second heating means extend beyond the upper surface of the tray. 
     
     
         3 . Furnace for testing materials according to  claim 2 , characterised in that it comprises screws to assemble the bell on the tray in a sealed manner, and springs assembled against the screws to tolerate a spacing between the bell and the tray in the event of high pressure in the enclosure. 
     
     
         4 . Furnace for testing materials according to  claim 1 , characterised in that the second adjustable heating means consist in a pointed filament extending beyond the upper surface of the tray. 
     
     
         5 . Method of characterising a material with heating under the effect of a mechanical energy, characterised in that it consists in evaluating a quantity of energy expended in the material by said mechanical energy, placing a specimen of the material in the furnace according to  claim 1 , and applying said quantity of energy to the specimen by the second heating means. 
     
     
         6 . Method of characterising the thermal behaviour of a material with heating under the effect of a fixed temperature, or a temperature ramp chosen by means of the furnace according to  claim 1 .