Liu Dexian1, Stephenson T F2, Korotkin M2, Metcalfe S2
Vale Inco Limited
(1.25 Fl Aurora Plaza, 99 Fu Cheng Road Shanghai, 200120, China)
(2.2060 Hadwen Road Mississauga, Ontario L5K 1Z9 Canada)
Abstract Fine Ni powder is often added to Co and bronze-based metal binder powders for diamond tool segments. Ni is a lower cost substitute for extra-fine Co powder and increases the toughness of Co-Fe diamond binders at the expense of lower hardness and bend strength. In bronze-based diamond binder segments, Ni increases hardness and yield strength. Several grades of Ni powder are used commercially with both Co and bronze-based diamond binders. This paper compares properties of diamond binders containing carbonyl Ni powders including standard Inco® T255, T123 PM and T 110 PM. Binder materials were made by ball milling or dry mixing of the fine carbonyl Ni and Fe powders with either XF Co or air atomized bronze (90/10 Cu/Sn) powders. Co-based powder blends were hot pressed at 20~35 MPa and 700 ℃ to 900 ℃. Bronze-based powder blends were cold pressed and sintered at 840 ℃. Apparent density, apparent hardness and bend strength (TRS) were compared for different binder compositions and processing conditions.