Fine grain niobium sheet via ingot metallurgy

Abstract

A method of making an alloy of niobium that includes: A) forming a blend comprising niobium powder and a powder of a metal selected from the group consisting of yttrium, aluminum, hafnium, titanium, zirconium, thorium, lanthanum and cerium and pressing the blend to form pressed blend; B) attaching the pressed blend to an electrode comprising niobium; C) melting the electrode and pressed blend under vacuum arc remelting conditions, such that the blend mixes with the melted electrode; D) cooling the melted electrode to form an alloy ingot; and E) applying thermo-mechanical processing steps to the alloy ingot to form a wrought product. The method provides a fully recrystallized niobium wrought product with a grain size finer that ASTM 5, that can be used to make deep drawn cups and sputtering targets.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a process for manufacturing niobium plates or sheets as well as uses thereof, such as for deep drawn cups and sputtering targets. [0002] Niobium ingots can be rolled to plate and sheet dimensions using known methods in the art. Such plates and sheets can be used, for example, by being deep drawn into cups for the synthetic diamond industry. The niobium foil used typically has an inconsistent and coarse grain size, which leads to poor flatness and smoothness of the deep drawn cup bottom. Poor flatness and / or smoothness (orange peel) result in a synthetic diamond that requires excessive grinding to correct deficiencies. The problem ultimately relates to a coarse grain structure in the niobium sheet. The coarse grain structure can also cause tearing of the sheet during deep-draw operations. [0003] The grain size of typical, commercially available niobium sheet is variable, ranging from an ASTM grain size of from 4 to 1...

AI Technical Summary

Problems solved by technology

The niobium foil used typically has an inconsistent and coarse grain size, which leads to poor flatness and smoothness of the deep drawn cup bottom.

Poor flatness and / or smoothness (orange peel) result in a synthetic diamond that requires excessive grinding to correct deficiencies.

The problem ultimately relates to a coarse grain structure in the niobium sheet.

The coarse grain structure can also cause tearing of the sheet during deep-draw operations.