Tough ISCAR Whiskered Ceramic Handles Roughing
ISCAR has developed a new line of ceramic turning inserts tough enough to tackle interrupted-cut finish turning of superalloys, as well as roughing of hard castings and hardened steel. Thus they extend the known benefits of ceramic machining to applications involving higher shock and impact loads and machining with coolant.
ISCAR’s new IW7 is available in round, square and rhombic. The inserts feature an improved alumina substrate with SiC whisker reinforcement. In trials involving roughing and interrupted-cut finishing, sometimes under coolant, these inserts have improved removal rates eight- to ten-fold compared with carbide inserts. Comparing it with other ceramics, turbomachinery manufacturers report substantial improvements with the IW7 for machining Inconel 718 and Waspalloy, Stellite and Rene. In some cases the inserts have enabled unattended turning of these high-value components.
An extra hard (Hv 2,100) substrate provides extreme wear resistance in hard materials, and the SiC whiskers add shock resistance. The insert can withstand machining heat; well enough to last at speeds that soften the metal being cut.
The new insert works best when clamped with ISCAR’s T-clamp toolholders. To reduce cutting forces and impact loads in roughing work, the company also recommends 15 or 45° lead angles.