A Method for Optimizing Grain Size and Uniformity of Tantalum Sheets

Abstract

The invention discloses a method for optimizing the grain size and uniformity of a tantalum plate, comprising: step 1, flattening a tantalum ingot with a circular cross-section at room temperature with a fast forging machine to obtain a rectangular cross-section Tantalum billet; Step 2, sawing, to obtain a tantalum billet with a square cross-section; Step 3, forging a round shape after heat preservation, to obtain a round billet; Step 4, the first annealing treatment, to obtain an annealed rod Billet; Step 5, extruding after heat preservation to obtain a slab with a rectangular cross-sectional shape; Step 6, annealing for the second time to obtain a slab after annealing; Step 7, rolling to obtain a plate; Step 8, annealing for the third time processing to obtain finished tantalum plates. The method of the present invention can realize the preparation of medium-thick tantalum plates of 5 mm to 20 mm, the grain size is better than 6.5 grades, the maximum grain size is ≤ 38 μm, the grain size in the thickness direction of the plate is uniform, and the grain size difference between the surface layer and the core is within 100 μm. Within 0.5 level.

Description

technical field [0001] The invention belongs to the technical field of material processing, and particularly relates to a method for optimizing the grain size and uniformity of a tantalum plate. Background technique [0002] Metal tantalum has high melting point, low vapor pressure, low evaporation rate at high temperature, low ductile-brittle transition temperature (DBTT) and special dielectric properties, and can be widely used in the preparation of integrated circuit sputtering targets; in addition, tantalum also has high density , a certain tensile strength and good ductility characteristics, compared with copper has a higher penetration, is also one of the ideal materials for the drug-type cover. Since the size and uniformity of the crystal grains directly affect the performance of the sputtered film and the performance of the drug mask, as the grain size is smaller, the deposition rate of the sputtered film is higher and the uniformity is better. The armor-piercing po...

AI Technical Summary

Problems solved by technology

However, in the prior art, the fineness and uniformity of the grain size in the thickness direction cannot be guaranteed when preparing plates with a thickness greater than 5mm, so that the finished plate not only has a grain size of more than 50 μm, but also has a grain size difference greater than 2 in the thickness direction. , can not meet the rapid development of integrated circuits and the needs of heavy blows

[0004] There are three reasons for the above phenomenon of medium and thick plates: one is that the raw material tantalum ingot grains are coarse and uneven, especially the original grains of the tantalum ingot melted by electron beam are abnormally coarse, and the edge of the ingot is slightly smaller The equiaxed crystals of tantalum have a size of about 10-50 mm, and the center is an abnormally thick columnar crystal, with a maximum size of 100 mm. Second, due to the poor forgeability of tantalum, even after repeated upsetting forging, the plastic deformation is distributed from the surface to the core. It is always uneven; the third is that the total processing rate of medium-thick plate rolling is small, and it is difficult to obtain plates with fine and uniform grains

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