Al-Zn-Mg-Cu alaşımlarının su verme hassasiyeti

Year 2017, Volume: 23 Issue: 8, 963 - 966, 28.12.2017

Funda Gül Koç , Mustafa Çöl Tanju Çeliker

Abstract

Al-Zn-Mg-Cu
alüminyum alaşımları sahip oldukları düşük yoğunluk, yüksek mukavemet, sertlik,
tokluk ve korozyon direnci özelliklerinden dolayı havacılık ve uzay
endüstrisinde geniş bir kullanım alanına sahiptir.  Bu çalışmada, 7075 serisi alüminyum alaşımının
su verme hassasiyeti alın su verme yöntemi kullanılarak incelenmiştir. Numuneye
480 °C’de 3 sa. süreyle çözeltiye alma işlemi uygulandıktan hemen sonra alın su
verme test düzeneğinde oda sıcaklığındaki su ile bir uçtan soğutma işlemi
uygulanmıştır. Soğutma işlemi esnasında numunenin boyuna kesiti boyunca meydana
gelen soğuma hızındaki değişimler K tipi termo-elemanlar vasıtasıyla eş zamanlı
olarak ölçülmüştür. Su verme işlemi sonrası numuneye 120 °C’de 24 sa. süre ile
suni yaşlandırma işlemi uygulanmıştır. Su verilen uçtan uzaklaştıkça malzemenin
sertlik, elektriksel iletkenlik ve mikroyapı özeliklerinde meydana gelen
değişimler incelenmiştir.

Keywords

Su verme hassasiyeti, Al-Zn-Mg-Cu alaşımları, Sertlik, Elektriksel iletkenlik, Mikroyapı

Quench sensitivity of Al-Zn-Mg-Cu alloys

Abstract

Al-Zn-Mg-Cu
aluminum alloys are extensively used in aviation and aerospace industries for
their high strength, hardness, toughness and corrosion resistance. In this
study, quench sensitivity of 7075 series aluminum alloy was investigated by
using end quench test. Specimens were solution treated at 480 °C for 3 hours
and then the specimens were immediately transferred to the end quenching rig
(<5s). Changes in the temperature of the specimen during the quenching process
were measured by using type K thermocouples. Quenched specimen was subjected to
artificial aging at 120 °C for 24 hours. The changes of hardness, electrical
conductivity and microstructure properties of the material as the distance from
quenched end of bar increases were investigated.

Keywords

Quench sensitivity, Al-Zn-Mg-Cu alloys, Hardness, Electrical conductivity, Microstructure

References

• Zhang Y, Yang S, Ji H. “Microstructure evolution in cooling process of Al-Zn-Mg-Cu alloy and kinetics description”. Transactions of Nonferrous Metals Society of China, 22, 2087-2091, 2012.
• Li P, Xiong B, Zhang Y, Li Z. “Temperature variation and solution treatment of high strength AA7050”. Transactions of Nonferrous Metals Society of China, 22, 546-554, 2012.
• Zhang J, Deng Y, Yang W, Hu S, Zhang X. “Design of the multi-stage quenching process for 7050 aluminium alloy”. Materials and Design, 56, 334-344, 2014.
• Tang J, Zhang X, Liu S, Liu W, Ouyang H, Li H. “Influence of quench-induced precipitation on aging behavior of Al-Zn-Mg-Cu alloy”. Transactions of Nonferrous Metals Society of China, 22, 1255-1263, 2012.
• Liu S, Zhang Y, Liu W, Deng Y, Zhang X. “Effect of step-quenching on microstructure of aluminum alloy 7055”. Transactions of Nonferrous Metals Society of China, 20, 1-6, 2010.
• ASM Handbook. Heat Treating. USA, ASM International, 1991.
• Zhang Y, Milkereit B, Kessler O, Schick C, Rometsch PA. “Development of continuous cooling precipitation diagrams for aluminium alloys AA7150 and AA7020”. Journal of Alloys and Compounds, 584, 581-589, 2014.
• Liu S, Zhong Q, Zhang Y, Liu W, Zhang X, Deng Y. “Investigation of quench sensitivity of high strength Al-Zn-Mg-Cu alloys by time-temperature-properties diagrams”. Materials and Design, 31, 3116-3120, 2010.
• Liu SD, Zhang XM, You JH. “Influence of aging on quench sensitivity effect of 7055 aluminum alloy”. Material Characterization, 59, 53-60, 2008.
• Robinson JS, Tanner DA, Truman CE, Paradowska AM, Wimpory RC. “The influence of quench sensitivity on residual stresses in the aluminium alloys 7010 and 7075”. Materials Characterization, 65, 73-85, 2012.
• Lin L, Liu Z, Bai S, Ying P, Wang X. “Effects of germanium on quench sensitivity in Al-Zn-Mg-Zr alloy”. Materials and Design, 86, 679-685, 2015.
• Li P, Xiong B, Zhang Y, Li Z, Zhu B, Wang F, Liu H. “Quench sensitivity and microstructure character of high strength AA7050”. Transactions of Nonferrous Metals Society of China, 22, 268-274, 2012.
• Deng Y, Wan L, Zhang Y, Zhang X. “Influence of Mg content on quench sensitivity of Al-Zn-Mg-Cu aluminum alloys”. Journal of Alloys and Compounds, 509, 4636-4642, 2011.