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guarantees increased resistance to brittleness
        and fracturing. Today, substrates of this type
        are commonly used in tools intended for
        turning operations.
        Until the 1980s carbide grades were uncoated.
        In order to make grades more universal and
        applicable to machining various engineering
        materials, tool manufacturers developed grades
        that contained various additives. The adoption
        of coating technologies has dramatically
        changed the world of machining; now the vast
        majority of carbide grades are coated. The
        inclusion of this new technology permitted the                 Fig.4.  ISCAR's CVD coating surface before (left)
        grades to focus on cutting specific material                   and after (right) SUMOTEC post coating treatment
        groups. The substrates contained fewer
        additives; therefore their structures became
        more uniform and stable, which further
        improved control during production.


        The introducing of coated carbides and on-going
        developments in this area has enabled significant
        increases in cutting speeds.

        For example 30 years ago, when turning
        grey cast iron the cutting speed used was
        approximately 100 m/min for inserts which
        were made from IC20 (ISCAR uncoated

                                                                       Fig.5.  Effect of the SUMOTEC treatment on a
                                                                       PVD coated surface;
                                                                       A - untreated surface
                                                                       B - treated surface























                                                                       Fig.6.  ISCAR's Grade IC6025 structure designed
                                                                       especially for turning ISO M materials



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