Method of forming a hard facing on the body of a tool

Claim 1

A METHOD FOR FORMING A HARD FACING ON A LESS WEARRESISTANT SUBSTRATE COMPRISING THE STEPS OF: DISPERSING A PLURALITY OF PARTICLES OF RELATIVELY HIGHER DENSITY CEMENTED METAL CARBIDE IN A SIZE RANGE OF FROM ABOUT 6 TO 30 U. S. SIEVE THROUGHOUT A RELATIVELY LOWER DENSITY METAL MATRIX, SAID PARTICLES HAVING A SUFFICIENTLY NONUNIFORM SIZE DISTRIBUTION TO BE PRESENT IN A PROPORTION IN THE RANGE OF FROM ABOUT 70 TO 85% BY VOLUME; FREEZING THE METAL MATRIX HAVING PARTICLES OF CEMENTED CARBIDE DISPERSED THEREIN IN A RELATIVELY THIN LARGER AREA PAD HAVING AN UPPER SURFACE AND A LOWER SURFACE; PLACING THE PAD ON A SUBSTRATE WITH THE AS-FROZEN UPPER SURFACE ADJACENT THE SUBSTRATE; AND MELTING THE MATRIX METAL FOR BONDING TO THE SUBSTRATE.

Claim 2

A METHOD FOR FORMING A HARD FACING ON A LESS WEARRESISTANT SUBSTRATE COMPRISING THE STEPS OF: DISPERSING A PLURALITY OF PARTICLES OF RELATIVELY HIGHER DENSITY CEMENTED METAL CARBIDE IN A SIZE RANGE OF FROM ABOUT 6 TO 30 U. S. SIEVE THROUGHOUT A RELATIVELY LOWER DENSITY METAL MATRIX, SAID PARTICLES HAVING A SUFFICIENTLY NONUNIFORM SIZE DISTRIBUTION TO BE PRESENT IN A PROPORTION IN THE RANGE OF FROM ABOUT 70 TO 85% BY VOLUME; FREEZING THE METAL MATRIX HAVING PARTICLES OF CEMENTED CARBIDE DISPERSED THEREIN IN A RELATIVELY THIN LARGER AREA PAD HAVING AN UPPER SURFACE AND A LOWER SURFACE; PLACING THE PAD ON A SUBSTRATE WITH THE AS-FROZEN UPPER SURFACE ADJACENT THE SUBSTRATE; AND MELTING THE MATRIX METAL FOR BONDING TO THE SUBSTRATE.

Claim 5

A method for forming a hard facing on a less wear-resistant substrate comprising the steps of: casting a wear pad in a substantially flat sheet having an upper face and a lower face, said wear pad comprising a plurality of particles of relatively denser cemented metal carbide bonded together by and dispersed throughout a relatively lower density Metal matrix, said particles having a sufficiently non-uniform size distribution to be present in a proportion in the range of from about 70 to 85% by volume, and wherein the pad has a minimum thickness in inches of about the U.S. Sieve opening in inches of the smallest cemented carbide particles times a factor equal to 0.075M1 + 0.3, where M1 is the U.S. Sieve size for the smallest cemented carbide particles, and a maximum thickness in inches of about the U.S. Sieve opening in inches of the largest cemented carbide particles times a factor equal to 0.20M2 + 1.0 where M2 is the U.S. Sieve size for the largest cemented carbide particles; and brazing the wear pad to a substrate so that the upper cast face of the wear pad is adjacent the substrate and the lower cast face of the pad is adjacent the wear surface.

Claim 6

A method for forming a hard facing on a less wear-resistant substrate comprising the steps of: casting a wear pad in a substantially flat sheet having an upper face and a lower face, said wear pad comprising a plurality of particles of relatively denser cemented metal carbide bonded together by and dispersed throughout a relatively lower density Metal matrix, said particles having a sufficiently non-uniform size distribution to be present in a proportion in the range of from about 70 to 85% by volume, and wherein the pad has a minimum thickness in inches of about the U.S. Sieve opening in inches of the smallest cemented carbide particles times a factor equal to 0.075M1 + 0.3, where M1 is the U.S. Sieve size for the smallest cemented carbide particles, and a maximum thickness in inches of about the U.S. Sieve opening in inches of the largest cemented carbide particles times a factor equal to 0.20M2 + 1.0 where M2 is the U.S. Sieve size for the largest cemented carbide particles; and brazing the wear pad to a substrate so that the upper cast face of the wear pad is adjacent the substrate and the lower cast face of the pad is adjacent the wear surface.

Claim 8

A method for forming a hard facing on a less wear-resistant substrate comprising the steps of: casting a wear pad in a substantially flat sheet having an upper face and a lower face, said wear pad comprising a plurality of particles of relatively denser cemented metal carbide of non-uniform size distribution bonded together by and dispersed throughout a relatively lower density metal matrix and, wherein the pad has a thickness equal to the U.S. Sieve opening in inches times a factor on the ordinate corresponding to that portion of the shaded area of FIG. 4 bounded on the abscissa by the minimum U.S. Sieve size and maximum U.S. Sieve size of the cemented carbide particles in the pad; and brazing the wear pad to a substrate so that the upper cast face of the wear pad is adjacent the substrate and the lower cast face of the pad is adjacent the wear surface.

Claim 9

A method for forming a hard facing on a less wear-resistant substrate comprising the steps of: casting a wear pad in a substantially flat sheet having an upper face and a lower face, said wear pad comprising a plurality of particles of relatively denser cemented metal carbide of non-uniform size distribution bonded together by and dispersed throughout a relatively lower density metal matrix and, wherein the pad has a thickness equal to the U.S. Sieve opening in inches times a factor on the ordinate corresponding to that portion of the shaded area of FIG. 4 bounded on the abscissa by the minimum U.S. Sieve size and maximum U.S. Sieve size of the cemented carbide particles in the pad; and brazing the wear pad to a substrate so that the upper cast face of the wear pad is adjacent the substrate and the lower cast face of the pad is adjacent the wear surface.