The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 21, 1995
Filed:
Nov. 29, 1993
Willard E Kemp, Houston, TX (US);
Fike Corporation, Blue Springs, MO (US);
Abstract
A process and apparatus for forming a hardened outer shell (40) on a refractory metal workpiece (36) preferably heated in a fluidized bed of metallic oxide particles (38) in an environment of an inert gas and a reactive gas with the reactive gas either oxygen or nitrogen. The workpieces (36) are heated in the fluidized bed to a temperature between 800.degree. F. and 1600.degree. F. for a period of over two hours to form hardened outer shell (40) in two layers (42, 44). Outer layer (42) is an oxide or nitride layer having a thickness (T1) between 10 microns and 25 microns. Inner layer (44) is a case hardened layer of the refractory metal having a thickness (T2) between 25 microns and 75 microns. In one embodiment (FIG. 3 ) workpieces (56) may be cold worked by peening from finely divided metal oxide particles (54) to provide a uniform surface texture for subsequent hardening.