MFE 201 Lecture Notes - Lecture 35: Tungsten Carbide, High-Speed Steel, Tungsten
31 Mar 2016
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Document Summary
Lowest friction: to minimize heating of the tool by chip friction. No chemical reactivity with workpiece to prevent reactions and adhesion. Toughness: to resist impact loads such as those in milling. Sti ness and strength: to minimize de ection and support greater cutting loads. Hot hardness: retaining hardness at high temperatures allows higher cutting speeds. Toughness: allows for interrupted cuts due to fracture resistance. No chemical reactivity leads to no sticking (bue, adhesive wear) Sti ness which leads to less de ection which makes for better accuracy. Strength which allows for higher loads, more demanding applications. Low thermal expansion leads to better dimensional accuracy. Cutting tool development has been an evolution: base material -> inserts -> coatings. Cutting edge technology (no pun intended) is a combination: holder/support, inserts (often composite), coating. Materials will be covered in a historical timeline, this makes more sense. The quest for better tool materials is due to a desire for greater machining productivity.
