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

Year 2023, , 315 - 327, 20.12.2023

Uğur Usta Betül Kafkaslıoğlu Yıldız

https://doi.org/10.47495/okufbed.1271545

Abstract

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.

Keywords

ZTA, Cr2O3, Mekanik Özellikler, Basınçsız Sinterleme

Supporting Institution

destekleyen kurum bulunmamaktadır

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

Abstract

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.

Keywords

ZTA, Cr2O3, Mechanical Properties, Pressureless sintering

References

• Arahori T., Whitney ED. Microstructure and mechanical properties of Al2O3-Cr2O3-ZrO2 composites. Journal of Materials Science 1988; 23: 1605-1609.
• Azhar AZA., Choong LC., Mohamed HM., Ratnam MM., Ahmad ZA. Effects of Cr2O3 addition on the mechanical properties, microstructure and wear performance of zirconia-toughened-alumina (ZTA) cutting inserts. Journal of Alloys and Compounds 2012; 513: 91–96.
• Azhar AZA., Mohamad H., Ratnam MM., Ahmad ZA. The effects of MgO addition on microstructure, mechanical properties and wear performance of zirconia-toughened alumina cutting inserts. Journal of Alloys and Compounds 2010; 497: 316–320.
• Bernardi MIB., Crispim SCL., Maciel AP., Souza AG., Conceição MM., Leite ER., Longo E. Synthesis and characterization of Al2O3/Cr2O3-based ceramic pigments. Journal of Thermal Analysis and Calorimetry 2004; 75: 475–480.
• Broniszewski K., Wozniak J., Czechowski K., Jaworska L., Olszyna A. Al2O3–Mo cutting tools for machining hardened stainless steel. Wear 2013; 303: 87–91.
• Chevalier J., Gremillard L., Virkar AV., Clarke DR. The Tetragonal-monoclinic transformation in zirconia: Lessons learned and future trends. Journal of the American Ceramic Society 2009; 92: 1901–1920.
• Feng L., Fahrenholtz WG., Hilmas GE., Watts J., Zhou Y. Densification, microstructure, and mechanical properties of ZrC–SiC ceramics. Journal of the American Ceramic Society 2019; 102: 5786–5795.
• Hassan AM., Naga SM., Awaad M. Toughening and strengthening of Nb2O5 doped zirconia/alumina (ZTA) composites. International Journal of Refractory Metals and Hard Materials 2015; 48: 338–345.
• Kafkaslıoglu Yıldız B., Tür YK. Effect of ZrO2 content on the microstructure and flexural strength of Al2O3–ZrO2 composites with the stored failure energy-fragmentation relations. Ceramics International 2021; 47: 34199–34206.
• Kafkaslıoğlu Yıldız B., Yılmaz H., Tür YK. Evaluation of mechanical properties of Al2O3–Cr2O3 ceramic system prepared in different Cr2O3 ratios for ceramic armour components, Ceramics International 2019: 45; 20575–20582.
• Li CL., Riu DH., Sekino T. Niihara K. Fabrication and mechanical properties of Al2O3 solid solution with low addition of Cr2O3. Key Engineering Materials 1999; 161–163.
• Lin HT., Nayak PK., Liu BZ., Chen WH., Huang JL. Mechanical properties of Al2O3–Cr2O3/Cr3C2 nanocomposite fabricated by spark plasma sintering. Journal of the European Ceramic Society 2012; 32: 77–83
• Lu FH., Chen HY., Hung CH. Degradation of CrN films at high temperature under controlled atmosphere. Journal of Vacuum Science and Technology A 2003; 21: 671-675.