Method and apparatus for fabrication of cobalt alloy composite inserts
AssigneeDennis Tool Company
InventorMahlon D. Dennis
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Abstract
This disclosure features a process of making a two part drill bit insert, namely, a body portion of hard particles such as tungsten carbide particles mixed in an alloy binding the particles. The alloy preferably comprises 6% cobalt with amounts up to about 10% permitted. The body is sintered into a solid member, and also joined to a PDC crown covering the end. The crown is essentially free of cobalt. The process sinters the crown and body while preserving the body and crown cobalt differences.
Claims22
A drill bit insert having at least two different regions and comprising:
- (a) an elongate body region comprising hard carbide particles in a cobalt alloy matrix;
- (b) an end located wear region comprising hard particles in a supportive cobalt alloy matrix;
- (c) wherein said two regions differ by at least about 5% in cobalt concentration before and after sintering;
- and
- (d) wherein said insert is formed as a unicast body by subjecting the entire elongate body region and end located wear region to substantially uniform microwave radiation.
A drill bit insert having at least two different regions and comprising:
- (a) an elongate body region comprising hard carbide particles in a cobalt alloy matrix;
- (b) an end located wear region comprising hard particles in a supportive cobalt alloy matrix;
- (c) wherein the two regions differ in cobalt concentration;
- and
- (d) wherein said insert is formed as a unicast body and sintered by subjecting the entire elongate body region and end located wear region without migration of cobalt between the two regions.
A method of making a sintered drill bit insert, the insert having an elongate body region comprising hard carbide particles in a cobalt alloy matrix and an end located wear region comprising hard particles in a supportive cobalt alloy matrix, the method comprising sintering the insert by subjecting it to substantially uniform microwave radiation, wherein said two regions differ by at least about 5% in cobalt concentration.
Dependencies are inferred from the claim text.