Analisis Pengaruh Variasi Holding Time Dan Metode Up/Step Quenching Pada Solution Treatment Terhadap Struktur Mikro Dan Kekerasan Pada Cu-15,9Zn-6,89Al Alloy

Ramadhan, Taufiq (2022) Analisis Pengaruh Variasi Holding Time Dan Metode Up/Step Quenching Pada Solution Treatment Terhadap Struktur Mikro Dan Kekerasan Pada Cu-15,9Zn-6,89Al Alloy. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini bertujuan untuk menganalisis variasi holding time dan metode perlakuan panas up quenching dan step quenching saat proses solution treatment paduan Cu-15,9Zn6,89Al alloy terhadap struktur mikro dan kekerasannya. Paduan u-15,9Zn-6,89Al didapatkanmelalui proses pengecoran dan diberikan perlakuan panas berupa homogenizing, annealing, dan solution treatment pada temperatur 850oC selama 10,30, dan 50 menit dan didinginkan cepat melalui proses up quenching dan step quenching. Dari hasil pengujian, didapatkan struktur mikro dari paduan membentuk fasa α, β, dan γ tanpa fasa martensit (β’). Fasa martensit tidak terbentuk akibat rendahnya temperatur mulai terbentuknya martensit (Ms) yang jauh dibawah temperatur ruang. Ditemukan juga adanya perbedaan jumlah fasa α akibat perbedaan laju pendinginan, dimana metode up quenching dengan media air di temperatur kamar menghasilkan laju pendinginan yang lebih cepat apabila dibandingkan dengan metode step quenching dengan media oli di temperatur 100oC. Besar butir yang dihasilkan juga memiliki perbedaan dimana seiring meningkatnya waktu tahan menyebabkan pertambahan ukuran butir sedangkan laju pendinginan yang lebih cepat mengurangi ukuran butir. Perbedaan jumlah fasa α dan ukuran butir akibat variasi metode quenching dan waktu tahan pada proses solution treatment menghasilkan perbedaan dari nilai kekerasan paduan. Secara keseluruhan, ukuran butir yang kecil akibat waktu tahan yang singkat seperti spesimen dengan waktu tahan selama 10 menit menghasilkan kekerasan yang lebih tinggi dibandingkan spesimen dengan waktu tahan selama 50 menit. Lalu, perbedaan metode quenching, mempengaruhi ukuran butir yang terbentuk dimana spesimen dengan metode up quenching yang memiliki besar butir yang lebih kecil dibandingkan spesimen dengan metode step quenching memiliki kekerasan yang lebih rendah akibat lebih banyaknya fasa α lunak yang terbentuk. Sehingga secara keseluruhan, kekerasan tertinggi terlihat pada spesimen as cast (290,67±2,08 HV) diikuti oleh specimen SQ10 (275,33±2,52 HV) dan kekerasan terendah terlihat pada spesimen UQ50 (240±2,65 HV).
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The purpose of this research is to analyze the variation in holding time and up quenching and step quenching heat treatment of Cu-15,9Zn-6,89Al Alloy to its microstructure and hardness. Cu-15,9Zn-6,89 alloy is made by casting and heat treated with homogenizing, annealing, and solution treatment at 850oC for 10, 30, and 50 minutes then rapidly cooled with up quenching and step quenching. From metallography testing result, it is shown that there are α, β, and γ phases without signs of martensite (β’) phases. The martensite phases couldn’t form because of the temperature in which martensite starts to form (Ms) is much lower than room temperature. It is also found that there is a difference in the amount of α phases caused by the difference in cooling rate, where up quenching in water at room temperature would cause a higher cooling rate in contrast to step quenching in oil at 100oC. The resulting grain size would also differ as the holding time increases causing a growth in grain size, but a faster cooling rate would inhibit the growth of grain. The difference in grain size caused by the variation in quenching method and holding time of solution treatment result in the difference in hardness value between specimens. Overall, a small grain size caused by a brief amount of holding time like specimen with a holding time of 10 minutes yield a higher hardness value of alloy compared to specimen with a holding time of 50 minutes. The difference in quenching method would affect the amount of α phases and the resulting grain size where up quenched specimens which has a lower grain size compared to step quenched specimens would have a lower hardness value because of its higher amount of soft α in its microstructure. So overall, the highest hardness value is seen in as cast specimen (290,67±2,08 HV) followed by SQ10 specimen (275,33±2,52 HV) and the lowest hardness value is seen in UQ50 specimen (240±2,65 HV). Sehingga secara keseluruhan, kekerasan tertinggi terlihat pada spesimen as cast diikuti oleh spesimen SQ10 (275,33±2,52 HV) dan kekerasan terendah terlihat pada spesimen UQ50 (240±2,65 HV).

Item Type:	Thesis (Other)
Additional Information:	RSMt 620.165 Ram a-1 - 2022
Uncontrolled Keywords:	Cu-Zn-Al Alloy, Holding Time, Up Quenching, Solution Treatment, Step Quenching
Subjects:	T Technology > TN Mining engineering. Metallurgy > TN690 Metallography. Physical metallurgy
Divisions:	Faculty of Industrial Technology > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Mr. Marsudiyana -
Date Deposited:	10 Feb 2025 02:10
Last Modified:	10 Feb 2025 02:10
URI:	http://repository.its.ac.id/id/eprint/116036

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