Mechanical Properties of ZTA-Cr2O3 Ceramic Composites Prepared with Nano and Micron Sized of Cr2O3 Powder on Different Ratios

Öz

In this study, the effect of Cr2O3 addition in different powder sizes on the densification and mechanical properties (elastic modulus, hardness and flexural strength) of ZTA composites were investigated. Nano and micron sized of Cr2O3 powder were added to the ZTA composite separately in different weight ratios (0.3, 0.6, 1%) and uniaxially dry pressing right after pressureless sintering at 1650°C/2 h in the air used as processing procedure. The relative density values of all the composites were close to each other for the Cr2O3 containing composites. A slight decrease in both densification and elastic modulus was observed with the addition of Cr2O3 due to the evaporation problem. Also, the addition of Cr2O3 did not have a serious effect on the hardness of the ZTA composites. The main effect of Cr2O3 addition on ZTA composites was seen for flexural strength. Compared to the ZTA, a nearly 7% increase in strength was obtained for 0.6%Cr2O3 containing composite prepared with micron sized Cr2O3 powder due to the generated compressive stresses in the grain boundary caused by solid solution formation.

Anahtar Kelimeler

• ZTA
• Cr2O3
• Mechanical Properties
• Pressureless sintering

Farklı oranlarda nano ve mikron boyutlu Cr2O3 tozu ile hazırlanan ZTA-Cr2O3 seramik kompozitlerin mekanik özellikleri

Öz

Bu çalışmada, farklı toz boyutlarında Cr2O3 ilavesinin ZTA kompozitlerinin yoğunlaştırma ve mekanik özelliklerine (elastik modülü, sertlik ve eğilme mukavemeti) etkisi incelenmiştir. Üretim prosedürü olarak nano ve mikron boyutunda Cr2O3 tozu farklı ağırlık oranlarında (%0.3, 0.6, 1) ZTA kompozite ayrı ayrı ilave edilmiştir ve tek eksenli kuru preslemeden hemen sonra havada 1650°C/2 saat basınçsız sinterleme yapılmıştır. Cr2O3 içeren kompozitler için tüm kompozitlerin relatif yoğunluk değerleri birbirine yakın çıkmıştır. Cr2O3 ilavesi ile buharlaşma probleminden dolayı hem yoğunlaştırma hem de elastisite modülünde hafif bir düşüş gözlenmiştir. Ayrıca Cr2O3 ilavesinin ZTA kompozitlerinin sertliği üzerinde ciddi bir etkisi olmamıştır. Cr2O3 ilavesinin ZTA kompozitler üzerindeki ana etkisi eğilme mukavemeti için görülmüştür. Mikron boyutunda Cr2O3 tozu ile hazırlanan %0,6 Cr2O3 içeren kompozitte, katı çözelti oluşumundan dolayı tane sınırlarında oluşan basma gerilmeleri nedeniyle ZTA'ya göre yaklaşık %7'lik mukavemet artışı elde edilmiştir.

Anahtar Kelimeler

• ZTA
• Cr2O3
• Mekanik Özellikler
• Basınçsız Sinterleme

Destekleyen Kurum

destekleyen kurum bulunmamaktadır

Kaynakça

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