Al-18Si Alaşımında Döküm Kalitesi, Mikroyapı Ve Mekanik Özellikler Arası İlişkinin İncelenmesi

Year 2018, Volume: 10 Issue: 1, 30 - 41, 29.01.2017

Muhammet Uludağ

https://doi.org/10.29137/umagd.419659

Cited By: 1

Abstract

Bu çalışmada, primer silis ve ötektik mikroyapı morfolojisine sahip
Al-18Si alaşımında döküm kalitesi, soğuma hızı ve sıvı durumda bekletme
sürelerinin mikroyapı ve mekanik özelliklere etkisi incelenmiştir. 10, 15 ve
20 mm kesit kalınlığına sahip üç farklı basamağı barındıran kum kalıplar
soğuma hızı farkı için kullanılmıştır. Al-18Si ötektik üstü alaşım SiC potada
ergitildikten sonra üç farklı bekletme sürelerine (0, 60 ve 120 dk.) tabi
tutularak kum kalıplara dökümler gerçekleştirilmiştir. Elde edilen döküm
parçalarından mikroyapı, porozite incelemeleri ve çekme testleri için
numuneler çıkarılmıştır. Elde edilen görüntüler üzerinde SigmaScan marka
görüntü analiz programı yardımı ile incelemeler ve elde edilen datalar
üzerinde de Minitab istatistiksel analiz yazılımı ile de analizler
gerçekleştirilmiştir. Elde edilen tüm verilerde %18 Si içeriğine sahip
Al-18Si ötektik üstü alaşımında bifilm varlığının silis oluşumunu ve buna
bağlı olarak da mekanik özellikleri değiştirdiği sonucuna varılmıştır.

Keywords

Al-18Si alaşımı, Porozite, Bifilm, Mekanik özellikler, Si morfolojisi

Investigation of the Relationship Between Casting Quality, Microstructure and Mechanical Properties in Al-18Si Alloy

Abstract

In this work, the effect of
melt quality, cooling rate and holding time over the microstructure and
mechanical properties of Al-18Si alloy was investigated. This alloy contains
primer silicon and eutectic microstructure. A sand mold that has 10, 15 and 20 mm
thickness that is in shape of a step mold was used. Al-18Si hypereutectic alloy
was melted in SiC crucible and the casting were completed after three different
holding time (0, 60 and 120 min.). Cast samples were subjected to
microstructure, porosity and mechanical analysis. The images were analyzed by
SigmaScan and the data were statically analyzed by Minitab. It was found that
bifilms initiated silicon formation and mechanical properties were related to
this mechanism

Keywords

Al-18Si alloy, Porosity, Bifilm, Mechanical properties, Si morphology

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