Title

The effects of degassing, grain refinement & Sr-addition on melt quality-hot tear sensitivity relationships in cast A380 aluminum alloy

Document Type

Article

Publication Date

8-1-2018

Subject Area

ARRAY(0x55f3ef7ab3b8)

Abstract

Hot tearing tendency of A380 with various element additions (Sr, Sr+Ti, Ti, B and B+Sr) was investigated. Constrained rod casting (CRC) hot tearing test method was used to characterize the hot tearing sensitivity. Reduced pressure test (RPT) samples were produced from each condition and all trials were repeated three times. Number density of pores on the cross section of RPT samples was calculated via digital image processing and statistical analysis was carried out. Microstructure analysis was carried out to observe the effect of alloying elements. Hot torn cross sections were subjected to SEM analysis. It was found that in aluminum alloys, the most deleterious defects, bifilms that are the cause of many defects, play an important role in initiating the hot tearing during solidification. It is important to note that the shape, size and distribution of bifilms are too complex. They act as heterogeneous nucleation site for liquid to separate and thus increase hot tearing.

Publication Title

Engineering Failure Analysis

Volume

90

First Page

90

Last Page

102

Digital Object Identifier (DOI)

10.1016/j.engfailanal.2018.03.025

ISSN

13506307

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