Bond for abrasive tool

A method of bonding an abrasive grit to a tool having a predominantly iron core, comprising the steps of:

• (1) blending to a uniform mixture a bond composition, the bond composition being a mixture of powder components, consisting essentially of
• (i) a Pre-alloy of about 50-80 wt % copper and about 15-25 wt % tin;
• and
• (ii) about 5-15 wt % titanium, and
• (iii) about 2-150 pbw silver per 100 pbw of the total of (i)-(ii),
• the weight percentages being based on the total of (i)-(ii);
• and
• (2) placing abrasive grains and the bond composition on a cutting surface of the core;
• and
• (3) heating the bond composition to a maximum brazing temperature of about 870° C. in a substantially oxygen-free atmosphere for a duration effective to liquefy a major fraction of the composition
• whereby a formation of intermetallics of tin and iron during bonding is avoided and, after stripping the bond composition from the Predominately iron core, a reconditioned core having dimensional precision suitable for industrial grinding is obtained.

A single layer metal bonded tool comprising

• (a) a predominantly iron core;
• and
• (b) abrasive grit bonded to the core by a brazed bond composition prepared from a mixture of metal Powder components, consisting essentially of
• (i) a pre-alloy of about 50-80 wt % copper and about 15-25 wt % tin;
• and
• (ii) about 5-15 wt % titanium, and
• (iii) about 2-150 pbw silver per 100 Pbw of the total of (i)-(ii),
• the weight percentages being based on the total of (i)-(ii),
• whereby the formation of intermetallics of tin and iron during brazing is avoided and, after stripping the bond composition from the predominately iron core, a reconditioned core having dimensional precision suitable for industrial grinding is obtained.

An abrasive tool having a predominantly iron core, wherein the tool is produced by a process comprising the steps of

• (1) blending to a uniform mixture a bond composition, the bond composition being a mixture of powder components, consisting essentially of
• (i) a pre-alloy of about 50-80 wt % copper and about 15-25 wt % tin;
• and
• (ii) about 5-15 wt % titanium, and
• (iii) about 2-150 pbw silver per 100 pbw of the total of (i)-(ii),
• the weight percentages being based on the total of (i)-(ii);
• (2) placing abrasive grains and the bond composition on a cutting surface of the core;
• and
• (3) heating the bond composition to a maximum brazing temperature of about 870° C. in a substantially oxygen free atmosphere for a duration effective to liquefy a major fraction of the composition
• whereby a formation of intermetallics of tin and iron during bonding is avoided and, after stripping the bond composition from the predominately iron core, a reconditioned core having dimensional precision suitable for industrial grinding is obtained.