COBEM99

S19 Usinagem dos Materiais

Title:

THE INFLUENCE OF MACHINING CONDITIONS ON SURFACE ROUGHNESS OF STEEL WORKPIECES MILLED WITH CEMENTED CARBIDE AND CORONITE ENDMILLS

Summary :

ABSTRACT. AMONG THE DIFFERENT MACHINING PROCESSES USED IN MANUFACTURING COMPANIES, THE MILLING PROCESS IS OUTSTANDING, TO ITS HIGH FLEXIBILITY AND HIGH CHIP REMOVAL RATE. HOWEVER, IT IS ONE OF THE MOST COMPLEX PROCESSES, DUE TO SEVERAL FACTORS THAT INFLUENCE ITS RESULTS. THE TECHNOLOGICAL DEVELOPMENT IN THE MACHINING FIELD AND THE DIFFERENT NEEDS CREATE BY THE SEVERAL KINDS OF MATERIALS TO BE CUT,LED TO THE DEVELOPMENT OF A LARGE VARIETY OF CUTTING TOOLS AND TOOL MATERIALS. AMONG THESE NEW TOOL MATERIALS IS CORONITE, WHICH IS A MATERIAL THAT HAS INTERMEDIATE PROPERTIES BETWEEN CEMENTED CARBIDE AND HIGH SPEED STEEL. THEREFORE, IT IS POSSIBLE TO USE INTERMEDIATE CUTTING SPEEDS WHEN USING CORONITE. NOWADAYS, WITH THE HIGH ROTATIONAL SPEED OF THE MODERN MACHINE TOOLS IT IS POSSIBLE TO USE CEMENTED CARBIDE MILLING CUTTERS OF SMALL DIAMETERS (SMALLER THAN 20 MM) AND, THEREFORE, A GOOD SURFACE FINISH CAN BE OBTAINED. THE MAIN GOAL OF THIS WORK IS TO COMPARE THE SURFACE QUALITY OF STEEL WORKPIECES MILLED BY CEMENTED CARBIDE AND CORONITE CUTTERS. TO REACH THIS GOAL, SEVERAL GROOVES WERE MILLED IN NA AISI 1045 STEEL WORKPIECE UNDER DIFFERENT CUTTING CONDITIONS. THE PURPOSE OF THIS EXPERIMENTS IS TO ANALYSE HOW PARAMETERS SUCH AS CUTTING SPEED AND FEED VELOCITY INFLUENCE SURFACE ROUGHNESS BEHAVIOR. THE PRINCIPAL CONCLUSIONS OF THIS WORK ARE: CUTTING SPEED IS VERY IMPORTANT TO SURFACE ROUGHNESS. WHEN FEED PER TOOTH WAS HIGH DUE A LOW VALUE FOR CUTTING SPEED, SURFACE ROUGHNESS WAS HIGHER THAN WHEN THE SAME HIGH FEED PER TOOTH WAS USED, BUT NOW, NOT DUE TO LOW CUTTING SPEED, BUT DUE TO HIGH FEED VELOCITY. TOOL MATERIAL DIDN T SHOW TO HAVE STRONG INFLUENCE ON SURFACE ROUGHNESS. KEY-WORDS: ENDMILLING, CORONITE, MACHINING CONDITIONS.

Author :

DINIZ, ANSELMO EDUARDO
ROSA, ALESSANDRA BERNARDIS

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