Preparation method of rare earth transition alloy rotary target for film coating of magneto-optical recording medium and prepared target of rare earth transition alloy rotary target

Abstract

The invention discloses a preparation method of a rare earth-transition alloy rotary target for film coating of a magneto-optical recording medium and a prepared target of the rare earth transition alloy rotary target. The method comprises the steps that rare earth transition metal alloy is prepared; rare earth transition metal alloy hollow target tubes are formed through vacuum pouring; the poured rare earth transition metal alloy target tubes are subjected to hot isostatic pressing; machining is conducted; and indium binding is conducted. The rare earth transition alloy rotary target prepared through the method is even in composition, the relative density can reach 99.9%, the purity can reach 99.99%, the length is not limited, the defects of rotary target composition segregation, high fragility and the like are overcome, the porosity of the target is lowered, and the target is made to stably discharge in the application process, so that the quality of a magneto-optical recording medium thin film is improved. In addition, the method is simple in process and convenient to operate, conventional sheaths and argon arc welding are not needed during hot isostatic pressing, subsequent procedures are reduced, and the target tubes can be directly subjected to hot isostatic pressing, so that the production cost is reduced.

Description

technical field [0001] The invention relates to a target material and target material preparation technology, in particular to a method for preparing a rare earth transition alloy rotating target material for coating a magneto-optical recording medium and the target material. Background technique [0002] Rare earth-transition metal (Nd, Pr, Sm, Ce, Gd, Tb, Dy-Fe, Co) targets are widely used in optical communications, magnetic storage coatings and other fields, which requires rare earth-transition alloy targets with high purity, High density, large size integration and other advantages. At present, vacuum casting and vacuum sintering methods are mainly used to prepare small-sized planar rare earth-transition metal targets. Although the oxygen content is lower than 500ppm during vacuum casting, the alloy composition is uneven and segregation occurs; although the sintering method has uniform composition, the oxygen content Above 2000ppm, it is not suitable for rare earth tran...

AI Technical Summary

Problems solved by technology

At present, vacuum casting and vacuum sintering methods are mainly used to prepare small-sized planar rare earth-transition metal targets. Although the oxygen content is lower than 500ppm during vacuum casting, the alloy composition is uneven and segregation occurs; although the sintering method has uniform composition, the oxygen content Higher than 2000ppm, especially unsuitable for rare earth transition metals that are easily oxidized

In addition, the utilization rate of large planar targets is low, between 20-30%, while the utilization rate of rotating targets reaches 80-90%. Large-size, high-density, high-utilization and low-rotating targets are the future targets development trend

Although the rotating target can be realized by vacuum casting, due to the composition segregation and the brittleness of the rare earth alloy target, it is difficult to prepare a large-size rotating target with uniform composition by casting.