ANALISIS KEROPOS PADA PENGELASAN LASER MIKRO KAPSUL TERAPI KANKER LAJU DOSIS RENDAH

DK Yoga, A Pujiyanto, M Subechi, R Awaludin

Abstract


Salah satu terapi pengobatan kanker adalah dengan menggunakan radioaktif yang dimasukkan ke dalam mikrokapsul untuk diimplan ke dalam jaringan tubuh pasien yang terkena kanker. Mikrokapsul terbuat dari bahan Ti6Al4V ditutup menggunakan las laser. Pada saat pengelasan terjadi proses perubahan fase padat ke cair dan sebaliknya. Proses pendinginan dalam pengelasan yang terlalu cepat dapat menyebabkan keropos karena adanya gas yang terjebak pada saat pemadatan. Waktu pencairan dan pemadatan pada pengelasan laser dipengaruhi oleh pulsa berkas laser dan aliran gas selubung . Pada penelitian ini digunakan las laser Nd-YAG dengan bentuk pulsa trapezium pada frekuensi 5 Hz ,pada daya 300 W dan 400 W serta variasi aliran gas selubung 20,18,15 dan 12 l/min. Hasil pengelasan setelah dibelah dan diamati menggunakan mikroskop stereo ditemukan adanya lobang keropos pada sampel las dengan aliran gas 20 l/min dan efisiensi energy laser turun dengan penambahan panjang durasi pulsa laser pada fase pendinginan. Untuk mencegah adanya keropos, pengelasan efektif menggunakan aliran gas 15 l/min.

Microcapsules containing radioisotope is one of methods used for cancer treatment. It is put in the microcapsule to be implanted to the body tissues of patient who is affected by cancer. The microcapsule was made of Ti6Al4V and sealed by using laser welding. A phase change from solid to liquid or vice versa occurred during the welding process. A fast cooling time in welding process can cause a loss of porosity due to a gas entrapment during solidification. The melting and solidification time of laser welding were affected by laser beam pulse and the flow of sealed gas. In this study, Nd-YAG laser was used in a shape of trapezium pulse. The study was carried out with a frequency, power and sealed gas flow of 5Hz, 300 and 400 W, and 20, 18, 15, 12 l/min, respectively. The welding product after splitting was further observed using a stereo microscope. The result revealed that a porous hole was found in welding samples in a gas flow of 20 l/min and a decrease of laser energy exist by the increasing of long duration laser pulses in cooling time. Laser welding process was also found to be effective in gas flow of 15 l/min.

Keywords


cancer therapy; microcapsules; laser welding

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References


Dash A, Saxena SK, Manolkar RB, Shanta A, Majali MA, & Venkatesh M. 2006. Development of miniature 125I Sources for The Treatment of Eye and Prostate Cancers, Final report of a coordinated research project IAEA- TECDOC 1512, Vienna, June 2006

Fuerschbach PW & Eislation GR. 2002. Effect of Laser Spot Weld energy and Duration on Melting and absorption, Science and Technology of Welding and Joining. 7(4): 241-246

Katayama S. Uchiumi S, Mizutani M, Wang J & Fujii K. Pentration and Porosity Prevention Mechanism in YAG Laser-MIG hybrid laser Welding. 2007. J Light Metal Welding Construction. 44 (3): 99-109

Kelkar G. Pulsed Laser Welding, WJM Technology, http://www.welding-consultant.com diunduh 29 Juli 2011.

Lee HK, Han HS. 2005. Optimization of Nd:YAG laser welding Parameter for Sealing Small Titanium Tube Ends, Material Science and Engineering A. 415: 149-155

WHO. 2008. Are the number of cancer cases increasing or decreasing in the world? http://www.who.int /features/qa/15/en/index.html diunduh 21/11 / 2011


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