Manufacturing Process for Matrix Drill Bits

Abstract

A process for reducing inclusions during manufacturing of a matrix drill bit comprises placing at least a first layer of a first matrix material in a matrix bit body mold. At least a second layer of a second matrix material is placed in the mold. A binder material is placed in the mold with the binder material disposed proximate the second layer of matrix material and a metal a blank. A graphite lid is placed on the mold. The mold and the materials disposed therein are heated to a selected temperature to cause the binder material to melt and to allow the hot, liquid binder material to infiltrate the second matrix material and the first matrix material, with the second matrix material operable to improve infiltration of the first matrix material by the hot, liquid binder material without using a flux material.

1 . A fluxless process for manufacturing a matrix drill bit comprising:
 placing at least a first layer of a first matrix material in a matrix bit body mold;   placing a metal blank in the mold;   placing at least a second layer of a second matrix material in the mold;   placing a binder material in the mold with the binder material disposed proximate the second layer of matrix material and the metal blank;   placing a graphite lid on the mold;   heating the mold and the materials disposed therein to a selected temperature to melt the binder material and to allow the melted binder material to infiltrate the second matrix material and the first matrix material, with the second matrix material operable to improve infiltration of the first matrix material by the melted binder material;   starting solidification of the hot, liquid binder material with the first matrix material before the hot, liquid binder material solidifies with the second matrix material; and   cooling the mold and the materials disposed therein to form a coherent composite matrix bit body securely engaged with the metal blank.   
     
     
         2 . The process of  claim 1  wherein the first matrix material is chosen from the group consisting, of: a cemented carbide material and a spherical carbide material. 
     
     
         3 . The process of  claim 1  wherein the second matrix material is chosen from the group consisting of a microcrystalline tungsten carbide material and a cast carbide material. 
     
     
         4 . The process of  claim 1  wherein the second matrix material is operable to improve infiltration of the hot, liquid hinder material throughout the first matrix material to minimize incomplete infiltration of the first matrix material by the hot, liquid binder material. 
     
     
         5 . A process for reducing inclusions during manufacturing of a matrix drill bit comprising:
 placing at least a first layer of a first matrix material in a matrix bit body mold;   placing a metal blank in the mold;   placing at least a second layer of a second matrix material in the mold;   placing a binder material in the mold with the binder material disposed proximate the second layer of matrix material and the metal blank:   placing a graphite lid on the mold;   heating the mold and the materials disposed therein to a selected temperature to cause the binder material to melt and to allow the hot, liquid binder material to infiltrate the second matrix material and the first matrix material, with the second matrix material operable to improve infiltration of the first matrix material by the hot, liquid binder material without using a flux material;   starting solidification of the hot, liquid binder material with the first matrix material before the hot, liquid binder material solidifies with the second matrix material; and   cooling the mold and the materials disposed therein to form a coherent composite matrix bit body securely engaged with the metal blank.   
     
     
         6 . The process of  claim 5  wherein the first matrix material is chosen from the group consisting of: a cemented carbide material and a spherical carbide material. 
     
     
         7 . The process of  claim 5  wherein the second matrix material is chosen from the group consisting of a microcrystalline tungsten carbide material and a cast carbide material. 
     
     
         8 . The process of  claim 5  wherein the second matrix material is operable to improve infiltration of the hot, liquid binder material throughout the first matrix material to minimize incomplete infiltration of the first matrix material by the hot, liquid binder material.