RESISTANCE OF BARIUM MULLITE CERAMIC AS RADIATION SHIELDING TOWARDS FIRE TEMPERATURE UP TO 1100˚C

Nur Syafika Suhaiman; Azuhar Ripin; Faizal Mohamed; Irman Abdul Rahman; Mohd Idzat Idris

Nur Syafika Suhaiman Nuclear Science Program, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
Azuhar Ripin Medical Physics Group, Malaysia Nuclear Agency, 43600 Kajang Selangor, Malaysia
Faizal Mohamed, Assoc Prof. Dr. Nuclear Science Program, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
Irman Abdul Rahman, Assoc Prof. Dr. Nuclear Science Program, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
Mohd Idzat Idris, Dr. Nuclear Science Program, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Keywords: Fire simulation, Lead equivalent thickness, Barium mullites ceramic

Abstract

Abstract

Barium mullite ceramics (BMC) is a potential radiation shielding produced by mixing a local powder of kaolin and barite through a conventional processing method. This ceramic will be used to replace the commercial radiation shielding such as lead because it is heavy and expensive. In addition, the integrity of lead will be degraded at high temperature due to its low melting point of 327.5˚C. This study was carried out to observe the resistance of barium mullite ceramic as radiation shielding towards fire temperature up to 1100˚C. Three samples of BMC were heated at 400˚C, 900˚C and 1100˚C each as a simulation in the event of a real fire. One sample was used as a reference (0˚C). Lead equivalent thickness (LET) tests were carried out with BMC of 4.5 mm thickness with capability value for X-ray machine from 60 kV – 120 kV before and after fire simulation test. The X-ray diffraction (XRD) tests and scanning electron microscope (SEM) observations were performed to evaluate the crystallinity properties and microstructures before and after fire simulation test, respectively. Results from LET tests showed that 4.5 mm thick BMC were equivalent to the range of 0.26 mmPb - 0.38 mmPb after the fire simulation. Meanwhile, celsian peaks were observed in XRD results at all temperatures. Furthermore, SEM observations showed no significant change in single phase of BMC even though it was heated at 1100˚C due to the high melting point of 1760˚C. From this study, it can be concluded that BMC performance as radiation shielding after the event of fire up to 1100˚C is consistent and has the potential to replace lead at X-ray room facility.

Abstrak

Seramik barium mullite (BMC) adalah berpotensi sebagai perisai sinaran yang dihasilkan melalui pencampurkan serbuk kaolin dan barit tempatan melalui kaedah pemprosesan secara konvensional. Seramik ini akan digunakan untuk menggantikan perisai sinaran komersial seperti plumbum kerana ia adalah berat dan mahal. Di samping itu, ketahanan pemerisaian bagi plumbum adalah berkurang pada suhu tinggi kerana plumbum mempunyai takat lebur yang rendah iaitu 327.5˚C. Kajian ini dijalankan untuk menguji ketahanan seramik barium mullite sebagai perisai sinaran pada suhu kebakaran sehingga 1100˚C. Tiga sampel BMC dibakar pada suhu 400˚C, 900˚C dan 1100˚C setiap satunya bagi tujuan simulasi sekiranya berlaku kebakaran sebenar. Satu sampel digunakan sebagai rujukan (0˚C). Ujian ketebalan kesetaraan plumbum (LET) telah dijalankan dengan BMC berketebalan 4.5 mm dengan nilai keupayaan tiub mesin sinar-X dari 60 kV - 120 kV sebelum dan selepas ujian simulasi kebakaran dilakukan. Ujian pembelau sinar-X (XRD) dan mikroskop imbasan elektron (SEM) dilakukan untuk mengenalpasti sifat kehabluran dan struktur mikro seramik sebelum dan selepas ujian pembakaran. Keputusan daripada ujian LET menunjukkan BMC berketebalan 4.5 mm adalah bersamaan dengan julat 0.26 mmPb - 0.38 mmPb selepas ujian simulasi kebakaran. Sementara itu, keputusan XRD menunjukkan puncak yang terhasil adalah fasa tunggal celsian pada semua suhu. Tambahan pula, pemerhatian SEM tidak menunjukkan perubahan ketara dalam fasa tunggal BMC walaupun ia dipanaskan pada suhu 1100˚C berikutan takat lebur yang tinggi iaitu 1760˚C. Daripada kajian ini, dapat disimpulkan bahawa prestasi BMC sebagai perisai sinaran selepas kejadian kebakaran sehingga 1100˚C adalah konsisten dan berpotensi untuk menggantikan plumbum di kawasan bilik sinar-X.