Properties of diamond tool binders with fine carbonyl Ni powder additions

摘要

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(R) 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 ℃. Bronzebased 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.