Platinum group alloy manufacturing method

Abstract

The present invention is a continuous founding-type melt ingot manufacturing process in which used is a plasma arc melting furnace in which a plasma arc column is formed between an electrode torch disposed inside and at an upper part of a vacuum chamber and a water-cooled copper crucible which is provided with a cavity having a cross sectional area S1 and which is disposed inside and at a lower part of the chamber. While the end portion of a raw material rod formed of a platinum group alloy is inserted into the plasma arc column and melted, the melted material is caused to drip onto a base material inside of the water-cooled copper crucible and form a molten pool. While the height of the liquid surface of the molten pool is maintained at a constant height by lowering the base material, the bottom portion of the molten pool is caused to solidify. The horizontal cross-sectional area S (mm2) and the length L (mm) of the melt ingot satisfy S1>=S>500, L>4 radical sign (S / Pi), the internal pressure of the chamber at the time of melting is at least 0.8atm, and the lowering speed is no more than 10mm / min.

Description

technical field [0001] The invention relates to a method for manufacturing a platinum group-based alloy, in particular to the manufacture of a molten ingot in the method for manufacturing a platinum group-based alloy. Background technique [0002] Platinum group-based alloys are designed by utilizing the heat resistance, oxidation resistance, and chemical resistance of platinum group metals, and are widely used as high-temperature components and / or corrosion-resistant products. Here, the platinum group metal refers to a generic term of Pt, Pd, Rh, Ir, Ru, and Os. [0003] The manufacturing process of platinum group-based alloys generally includes a compounding process of alloy raw materials, a melting process, a plastic processing process, etc., and the melting method is divided into several types. The melting point of platinum group metals, which are the main components, is very high, so an induction heating melting furnace or an energy beam melting furnace is used. [00...

AI Technical Summary

Problems solved by technology

[0008] Regarding vacuum plasma melting and / or electron beam melting, there is usually the ability to continuously cast a large amount of alloys compared to non-consumable electrode type arc melting, and since the melting atmosphere is vacuum, impurities can be evaporated and removed (refining effect), so It is suitable for the melting of pure metals, but when melting alloys, the constituent elements with high vapor pressure evaporate more, which changes the composition of the alloy

[0009] In this way, the melting method widely used in the past has limitations in producing a large amount of platinum-group-based alloys without compositional fluctuations with good yields.

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