The new IW7 grade is suitable for turning Ni-based super alloys (e.g. Inconel), Co-based super alloys (e.g. Stellite) and for roughing hard castings and hardened steel.

Main Advantages

• High hardness (Hv 2,100)
• High fracture toughness due to SiC (silicon carbide) whisker
  reinforced ceramics
• Excellent thermal shock resistance, which enables using coolant
  and interrupted cut machining
• Excellent for roughing and semi-finishing operations at 8-10 times
  faster cutting speeds when compared with carbide grades
• Good oxidation resistance due to its alumina substrate

As IW7 maintains high hardness at very high temperatures, super alloys and hard materials can be machined at high cutting speeds. The heat generated during high cutting speeds causes the material being cut to soften and thus reduces the cutting forces.

Recommendations

• Use ISCAR T-type clamp toolholders designed for ceramic inserts.
• For roughing applications always choose the strongest insert shape
  possible: round or square with a large corner radius.
• 15° or 45° lead angle is recommended.
• Chamfered entry and exit will reduce notch wear to improve
  tool life and surface finish.
• Select the largest possible corner radius and thickest insert.
• Use toolholders or boring bars with the largest possible
  cross section and minimal overhang for best stability.
• Heavy metal or carbide boring bars should be preferred.

The IW7 grade was developed to compete against competitors’ grades such as: WG300 (Greenleaf), KY4300 (Kennametal), CC670 (Sandvik), etc.

Recommended cutting conditions for Inconel, Stellite,
Waspalloy and Hastelloy
Cutting speed (Vc) =150-450 m/min
Feed rate (f) =0.1-0.2 mm/rev
Depth of cut (Ap) =0.5-3 mm
Coolant - dry & wet