Mekanik Alaşımlama Yöntemi ile Üretilen AA7075 Al Alaşımlarının Mikroyapısal ve Mekanik Özellikleri

Year 2022, Issue: 35, 54 - 61, 07.05.2022

Kemal Doğan , Mustafa Acarer , Yasin Eker , Emin Salur

https://doi.org/10.31590/ejosat.1041205

Abstract

Bu çalışmada, mekanik alaşımlama ve sinterleme yöntemleri ile AA7075 malzemelerinin üretilmesi amaçlanmıştır. Ayrıca, bu çalışmanın temel amacı, farklı bilyeli öğütme sürelerinin toz ve sinterlenmiş numuneler üzerindeki etkisini araştırmaktır. Öğütülmüş tozlar ve sinterlenmiş numuneler, farklı karakterizasyon teknikleri ile kapsamlı bir şekilde incelenmiştir. Başlangıçta, hazır olarak temin edilen AA7075 alaşım tozu, farklı öğütme sürelerinde gezegensel yüksek enerjili bilyeli öğütme cihazı ile öğütülmüştür. Ticari kalite AA7075 tozların başlangıç partikül boyutu 46 µm olarak hesaplanırken, 8 saatlik öğütülmüş tozların ortalama partikül boyutu 22 µm olarak ölçülmüştür. Öğütülmüş AA7075 alaşım tozların morfolojik özellikleri üzerindeki farklı öğütme sürelerinin (yani 0,5, 1, 2, 4 ve 8 saat) etkisi, taramalı elektron mikroskobu (SEM) analizi ve partikül boyut analizleri ile araştırılmıştır. Ek olarak, öğütülmüş tozların kristalografik özelliklerindeki farklılıkları gözlemlemek için X-ışını toz kırınımı (XRD) yapılmıştır. Toz hazırlama ve karakterizasyon aşamalarından sonra, üretilen AA7075 numunelerinin mekanik özelliklerine öğütme işleminin farklı aşamalarının etkisini belirlemek amacıyla, öğütülen bu tozlar soğuk pres ve ardından sinterleme işlemi ile konsolide edilmiştir. Deneysel sonuçlara göre, öğütme süresi son aşamaya (8 saat) ulaştığında, sinterlenmiş AA7075'in bağıl yoğunluğunun %7 azaldığı, buna karşın aynı üretim geçmişi ile üretilen saf AA7075 numunesine göre sertliğin %130 arttığı gözlemlenmiştir.

Keywords

AA7075, Bilyeli Öğütme, Mikroyapı, Mekanik Özellikler

Microstructural and Mechanical Properties of AA7075 Al Alloys Produced via Mechanical Alloying Process

Abstract

In this study, it is aimed to produce AA7075 materials by mechanical alloying and sintering methods. Besides, the main purpose of this study is to investigate the effect of different ball milling times on the powder and sintered samples. The milled powders and sintered samples were thoroughly investigated by different characterization techniques. Initially, AA7075 alloy powders were milled by planetary high-energy ball milling device with different milling times. While the initial particle size of commercial grade AA7075 powders were calculated 46 µm, the average particle size of the 8 hours milled powders measured as 22 μm. The effect of different milling times (i.e., 0.5, 1, 2, 4 and 8 hours) on the morphological properties of AA7075 milled powders were investigated by scanning electron microscopy (SEM) and particle size analyses. In addition, X-ray powder diffractometry (XRD) was performed to observe the differences in the crystallographic properties of the milled powders. After the powder preparation and characterization stages, in order to determine the effect of the different phases of milling process on the mechanical properties of the produced AA 7075 samples, these milled powders were consolidated via cold press followed by sintering process. According to experimental outcomes, it was observed that when the milling time reached the final stage (8 hours), the relative density of bulk AA7075 decreased by 7%, in contrast the hardness increased by 130% as compared to pure AA7075 sample fabricated by same producing history.

Keywords

AA7075, Ball Milling, Microstructure, Mechanical Properties

References

• Abu-Oqail, A., Wagih, A., Fathy, A., Elkady, O., & Kabeel, A. (2019). Effect of high energy ball milling on strengthening of Cu-ZrO2 nanocomposites. Ceramics International, 45(5), 5866-5875.
• Aslan, A., Salur, E., Düzcükoğlu, H., Şahin, Ö. S., & Ekrem, M. (2021). The effects of harsh aging environments on the properties of neat and MWCNT reinforced epoxy resins. Construction and Building Materials, 272, 121929.
• Basariya, M. R., Srivastava, V., & Mukhopadhyay, N. (2014). Microstructural characteristics and mechanical properties of carbon nanotube reinforced aluminum alloy composites produced by ball milling. Materials & Design, 64, 542-549.
• Chen, B., Li, S., Imai, H., Jia, L., Umeda, J., Takahashi, M., & Kondoh, K. (2015). Carbon nanotube induced microstructural characteristics in powder metallurgy Al matrix composites and their effects on mechanical and conductive properties. Journal of Alloys and Compounds, 651, 608-615.
• Güneş, A., Salur, E., Aslan, A., Kuntoğlu, M., Giasin, K., Pimenov, D. Y., . . . Şahin, Ö. S. (2021). Towards analysis and optimization for contact zone temperature changes and specific wear rate of metal matrix composite materials produced from recycled waste. Materials, 14(18), 5145.
• Nazik, C., Tarakcioglu, N., Ozkaya, S., Erdemir, F., & Canakci, A. (2016). Determination of effect of B 4 C content on density and tensile strength of AA7075/B 4 C composite produced via powder technology. International Journal of Materials, Mechanics and Manufacturing, 4(4), 251-261.
• Salur, E., Acarer, M., & Nazik, C. (2021). Mekanik Alaşımlama Süresinin Toz Metalurjisi ile Üretilen AA7075 Matrisli Nanokompozit Malzemelerinin Sertliklerine Etkisi. Journal of the Institute of Science and Technology, 11(3), 2218-2231.
• Salur, E., Acarer, M., & Şavkliyildiz, İ. (2021). Improving mechanical properties of nano-sized TiC particle reinforced AA7075 Al alloy composites produced by ball milling and hot pressing. Materials Today Communications, 27, 102202.
• Salur, E., Aslan, A., Kuntoglu, M., Gunes, A., & Sahin, O. S. (2019). Experimental study and analysis of machinability characteristics of metal matrix composites during drilling. Composites Part B: Engineering, 166, 401-413.
• Salur, E., Aslan, A., Kuntoğlu, M., & Acarer, M. (2021). Effect of ball milling time on the structural characteristics and mechanical properties of nano-sized Y2O3 particle reinforced aluminum matrix composites produced by powder metallurgy route. Advanced Powder Technology, 32(10), 3826-3844.
• Salur, E., Nazik, C., Acarer, M., Şavklıyıldız, İ., & Akdoğan, E. K. (2021). Ultrahigh hardness in Y2O3 dispersed ferrous multicomponent nanocomposites. Materials Today Communications, 28, 102637.
• Shkodich, N., Rogachev, A., Vadchenko, S., Moskovskikh, D., Sachkova, N., Rouvimov, S., & Mukasyan, A. (2014). Bulk Cu–Cr nanocomposites by high-energy ball milling and spark plasma sintering. Journal of alloys and compounds, 617, 39-46. Suryanarayana, C. (2001). Mechanical alloying and milling. Progress in materials science, 46(1-2), 1-184.
• Şavklıyıldız, İ. In-Situ Strain Measurement on Al7075 Plate by Using High Energy Synchrotron Light Source. Avrupa Bilim ve Teknoloji Dergisi(23), 435-439.
• Şavklıyıldız, İ., & Demir, A. Flash Sintering Effect on PMN-PT Ceramics. El-Cezeri Journal of Science and Engineering, 8(2), 793-799. Tekin, M., Polat, G., Kalay, Y. E., & Kotan, H. (2021). Grain size stabilization of oxide dispersion strengthened CoCrFeNi-Y2O3 high entropy alloys synthesized by mechanical alloying. Journal of Alloys and Compounds, 887, 161363.
• Usca, Ü. A., Uzun, M., Kuntoğlu, M., Sap, E., & Gupta, M. K. (2021). Investigations on tool wear, surface roughness, cutting temperature, and chip formation in machining of Cu-B-CrC composites. The International Journal of Advanced Manufacturing Technology, 116(9), 3011-3025.
• Usca, Ü. A., Uzun, M., Kuntoğlu, M., Şap, S., Giasin, K., & Pimenov, D. Y. (2021). Tribological aspects, optimization and analysis of Cu-B-CrC composites fabricated by powder metallurgy. Materials, 14(15), 4217.
• Varol, T., & Ozsahin, S. (2019). Artificial neural network analysis of the effect of matrix size and milling time on the properties of flake Al-Cu-Mg alloy particles synthesized by ball milling. Particulate Science and Technology, 37(3), 381-390.
• Xu, R., Tan, Z., Xiong, D., Fan, G., Guo, Q., Zhang, J., . . . Zhang, D. (2017). Balanced strength and ductility in CNT/Al composites achieved by flake powder metallurgy via shift-speed ball milling. Composites Part A: Applied Science and Manufacturing, 96, 57-66.
• Zebarjad, S. M., & Sajjadi, S. (2006). Microstructure evaluation of Al–Al2O3 composite produced by mechanical alloying method. Materials & design, 27(8), 684-688.