COBEM99

S19 Usinagem dos Materiais

Title:

STUDY OF THE ULTRAPRECISION MACHINING OF BRITTLE MATERIALS THROUGH ACOUSTIC EMISSION

Summary :

ABSTRACT: THE INCREASING INTEREST IN ULTRAPRECISION MACHINING, SPECIALLY IN THE OPTICAL ELECTRONIC INDUSTRY, HAS PROMPTED RESEARCH IN BRITTLE MATERIALS MACHINING. THESE MATERIALS ARE CHARACTERIZED BY THE ONSET OF BRITTLE FRACTURE BEFORE CONSIDERABLE DUCTILE FLOW TAKE PLACE UNDER MOST THE CUTTING CONDITIONS. HOWEVER, WHEN APPROPRIATE CUTTING CONDITIONS ARE USED, IE, FEED RATE AND DEPTH OF CUT, IT HAS BEEN FOUND THAT MATERIAL CAN BE REMOVED IN SUCH A WAY THAT FREE SURFACES CAN BE OBTAINED. APPROPRIATE MONITORING TECHNIQUES SHOULD BE APPLIED TO KEEP THESE CUTTING CONDITIONS.WHEN THESE CONDITIONS ARE WELL KNOWN AND CONTROLLED APPROPRIATE MONITORING TECHNIQUE CAN BE APPLIED. IN THIS WORK, VIABILITY OF AE AS MONITORING TECHNIQUE OF BRITTLE MATERIALS MACHINING WAS ASSESSED. SINGLE CRYSTAL SILICON WAFERS WERE DIAMOND TURNED AND THE AE SIGNAL GENERATED DURING THE CUTTING PROCESS WAS CORRELATED WITH THREE DISTINCT MATERIAL REMOVAL SITUATIONS: BRITTLE MODE, PARTIALLY BRITTLE AND DUCTILE MODE.

Author :

da Silva, Helder Augustus Treviso
Duduch, Jaime Gilberto
Jasineviccius, Renato G.

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