Characterisation of SiC electron beam irradiated
Abstract
Abstract
SiC possesses great potential as a structural or semiconductor material under radiation settings, due to the fact that it has excellent high temperature properties, radiation resistance and chemical stability. The exposure of SiC to radiation causes atomic scale defects via the displacement and the ionizations of target atoms, induced by incident energetic particles. In this work, SiC powder was pressed to form pellets, and was in turn sintered at a heating rate of 6 °C/min to 1400 °C for 2 hours. For irradiation testing, SiC pellets were irradiated (EPS-3000, 3.0 MeV, 10 mA) at a speed of 1.11 ms-1, and total radiation dosage of 200 kGy. After irradiation, the pellets were allowed to cool and sent for morphological analysis using the scanning electron microscopy (SEM) and atomic force microscopy (AFM), X-ray diffraction (XRD) for phase identification, hardness test and thermal expansion characteristics up to 500 °C. The results show that the hardness for post-irradiated samples are capable of withstanding loads of (122.5 HVF), compared to unirradiated samples (118.7 HVF). The amorphous content of the samples increases after irradiation, however, other trace element or phase composition changes were undetected. The results show that the surface roughness of the irradiated samples increased. Furthermore, the morphological analysis of the identified irradiated sample detected the diffusion of surface particles, which was assumed to be the factor that caused the enhancement of the hardness and thermal expansion coefficient.
Abstrak
SiC mempunyai potensi besar sebagai bahan struktur atau semikonduktor di bawah tetapan radiasi, kerana ia mempunyai sifat suhu tinggi yang sangat baik, rintangan radiasi dan kestabilan kimia. Pendedahan SiC ke radiasi menyebabkan kecacatan skala atom melalui anjakan dan ionisasi atom sasaran, disebabkan oleh zarah-zarah bertenaga yang bertenaga. Dalam kerja ini, serbuk SiC ditekan untuk membentuk pelet, dan kemudian disinter pada kadar pemanasan 6 ° C / min hingga 1400 ° C selama 2 jam. Untuk ujian penyinaran, pelet SiC telah disinari (EPS-3000, 3.0 MeV, 10 mA) pada kelajuan 1.11 ms-1, dan jumlah dos radiasi sebanyak 200 kGy. Selepas penyinaran, pelet dibenarkan untuk menyejuk dan dihantar untuk analisis morfologi menggunakan mikroskop elektron pengimbasan (SEM) dan mikroskopi daya atom (AFM), X-ray difraksi (XRD) untuk pengenalan fasa, ujian kekerasan dan ciri pengembangan haba sehingga 500 ° C. Keputusan menunjukkan bahawa kekerasan bagi sampel selepas penyinaran mampu menampung beban (122.5 HVF), berbanding dengan sampel tidak beriregrasi (118.7 HVF). Kandungan amorf sampel meningkat selepas penyinaran, bagaimanapun, unsur surih atau perubahan komposisi fasa tidak dapat dikesan. Keputusan menunjukkan bahawa kekasaran permukaan sampel yang diserap meningkat. Di samping itu, analisis morfologi sampel yang disiradiasi mengesan penyebaran zarah permukaan, yang dianggap sebagai faktor yang menyebabkan peningkatan kekerasan dan pekali pengembangan haba.
