Iscar develops wear and shock-resistant whisker reinforced ceramic inserts

Iscar has developed its Isoturn IW7 range of advanced ceramic turning inserts to be tough enough to tackle the interrupted-cut finish-turning of superalloys. In addition, the inserts are able to undertake the roughing of both hard castings and hardened steel.

Available in round, square and rhombic forms, Isoturn IW7 inserts feature an improved alumina substrate with SiC whisker reinforcement. In trials involving roughing and interrupted-cut finishing, sometimes under coolant, Iscar says the inserts have improved removal rates by eight to 10 times compared with carbide inserts. Also, the firm says, turbo machinery manufacturers report substantial improvements when using IW7 for machining Inconel 718, Waspalloy, Stellite and Rene, in comparison with other ceramics. In some cases, the new inserts have even enabled unattended turning of high value components. IW7's extra hard (Hv 2,100) substrate provides extreme wear resistance in hard materials, while the use of SiC whiskers adds high levels of shock resistance. In addition, the new Iscar insert is able to withstand machining heat to the extent that it will last at speeds that soften the metal being cut. For best results, Iscar recommends using its own T-clamp toolholders with the IW7 inserts pluslead angles of 15 or 45° to reduce both cutting forces and impact loads during roughing work.