Method for removing prior particle boundary and hole defect of powder metallurgy high-temperature alloy

Abstract

A method for removing prior particle boundaries and hole defects of a powder metallurgy high-temperature alloy. The method includes performing mechanical ball milling treatment on an atomized powder, thermosetting the powder to form a shape, and preparing a powder metallurgy high-temperature alloy.

Description

BACKGROUND[0001]1. Field of the Disclosure[0002]The disclosure relates to a method for removing prior particle boundaries and hole defects of a powder metallurgy high-temperature alloy, and belongs to the powder metallurgy material field.[0003]2. Description of Related Art[0004]Defects, such as prior particle boundaries (PPB), internal holes, or thermal induction holes of a powder metallurgy high-temperature alloy are main defects of a powder high-temperature alloy, and are difficult to be removed once formed, and severely reduce mechanical properties of an alloy.[0005]With respect to the defect of prior particle boundaries of the powder metallurgy high-temperature alloy, Chinese patent CN102409276A discloses a method for removing prior particle boundaries of a powder metallurgy high-temperature alloy, comprising: performing high-temperature solution treatment on a powder metallurgy high-temperature alloy after direct hot isostatic pressing at a high-temperature solution treatment t...

AI Technical Summary

Benefits of technology

The present invention proposes a method for improving mechanical properties of powder metallurgy high-temperature alloys by performing ball milling treatment on atomized powder to activate surfaces, remove internal hollow defects, and obtain solid powder with high surface activity. The resultant powder has improved comprehensive mechanical properties and can effectively remedy prior boundaries and hole defects in thermosetting forming. The method is simple and efficient for large-scale preparation and application.

Problems solved by technology

Defects, such as prior particle boundaries (PPB), internal holes, or thermal induction holes of a powder metallurgy high-temperature alloy are main defects of a powder high-temperature alloy, and are difficult to be removed once formed, and severely reduce mechanical properties of an alloy.

Simultaneously, since the blank is limited by a mold cavity, intracrystalline deformation of the blank in the state of pressure stress is difficult, and thus the development of various original microscopic defects in a deformed body can be inhibited.

Limited by processing factors, the effect of removing the prior boundaries of powder particles is limited, or industrial application cannot be implemented.

Therefore, the powder hollow defects are main sources of the hole defects of the powder high-temperature alloy.

A hollow center formed inside atomized powder is completely sealed, and is difficult to be removed in a subsequent powder forming process, and resides inside a material to form a residual hole.

Residual gases sealed in atomization hollow defects expand in a subsequent heat treatment process to form thermal induction holes, or induce cracks.

The holes severely reduce mechanical properties of a powder high-temperature alloy, in particular, creep rupture life and fatigue properties.

A screening method can remove large-particle-size hollow powder, but cannot completely remove hollow powder, because hollow defects also occur to screened small-size powder.

However, characteristics of an atomization process determine that the control atomization process can only reduce a powder hollow ratio, but cannot completely remove powder hollow defects.

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