Phase determination of ZrB 2 -B 4 C ceramic composite material using XRD and rietveld refinement analysis Saikat Mandal a,⇑ , Ayan Pramanick a , Shirshendu Chakraborty b , Partha Pratim Dey a a Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India b CSIR – Central Glass and Ceramic Research Institute, Jadavpur, Kolkata 700032, India article info Article history: Received 24 December 2019 Received in revised form 2 April 2020 Accepted 8 April 2020 Available online xxxx Keywords: UHTC ZrB 2 XRD Rietveld refinement abstract In this work, the Spark plasma sintering technique has been used to sinter ZrB 2 -B 4 C (20 wt%) composite at 2100 °C and 50 MPa uniaxial pressure for 15 min soaking in an argon atmosphere. XRD analysis has been carried out on the sintered sample to analyze the different phases present in the ZrB 2 -B 4 C compos- ite. The Rietveld refinement technique has been used to analyze the crystal structure, the unit cell infor- mation such as space group, cell position, cell angles and atomic distances of the composite material using FULLPROF software. Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Conference on Processing and Characterization of Materials. 1. Introduction For the past few decades, the attention of the researchers is on ultrahigh temperature ceramics (UHTCs) to make important parts such as wing edges and sharp nose of reusable reentry vehicles. UHTCs are the materials that can withstand temperature more than 3000 °C even in adverse condition, possesses excellent mechanical properties and good chemical stability [1,2]. Because of all those properties, UHTC and its composites possess the poten- tial to withstand the extreme environment [3]. One of the most important materials of the UHTCs group is Zirconium di-boride (ZrB 2 ); apart from the high melting point, it also possesses inherent high thermal conductivity, relatively high electrical conductivity [4–7]. The sintering ability of ZrB 2 powder is low due to its strong covalent bond, and the density is relatively high (6.08 g/cc), so the addition of element of comparatively low density namely B 4 C (2.52 g/cc) may produce a lighter composite with comparatively higher hardness than the spark plasma sintered monolithic sam- ples[8]. In this research work, the Rietveld Refinement and pattern fit- ting technique were used for the quantitative analysis of the differ- ent phases, crystal structure, the unit cell information such as space group, cell position, cell angles and atomic distances [9,10] of Spark plasma sintered ZrB 2 -B 4 C composite from the XRD data using FULLPROF software. 2. Experimental procedure Zirconium Di-Boride (ZrB 2 -Grade B) and Boron Carbide (B 4 C- Grade HD15) powders were procured from H.C. Starck, Germany. According to the company data, impurities in ZrB 2 powder are (in mass fraction) oxygen contain 1.5%, Carbon 0.2%, Nitrogen 0.25%, Fe 0.1%, and Hf 0.2% and in B 4 C impurities are oxygen 1.8%, Nitrogen 0.7%, Si 0.15%, Fe 0.1%, and Al 0.05%. The powder mixture of ZrB 2 and B 4 C with 80 and 20 wt% was prepared by hand mixing using an agate mortar pestle in methyl ethyl ketone med- ium and then dried in an oven for 2 h at 150 °C temperature. The dried powder was sintered by using an SPS furnace (HP D 25, FCT System GmbH, Germany) with the parameters shown in Table 1. To minimize the reaction between the graphite die, and powder mixture, the inner wall of the graphite mould and the outer surface of the plunger was lined with a thin graphite sheet. A cover was used in the outer wall to reduce heat loss due to radi- ation. The sintered samples were ground both sides by automatic silicon carbide wheel grinder for the removal of the graphite sheet from the surfaces. Bulk density of the sample was measured by standard Archi- medes water immersion principle in a double-distilled water med- ium, and the theoretical density was calculated by using standard mixing rule considering the theoretical density of ZrB 2 = 6.085 and B 4 C = 2.52. For the phase determination of the samples, the X-ray Diffrac- tion test (XRD) was conducted at room temperature using Cu Ka radiation (k = 0.15418 nm). The XRD data were recorded with a https://doi.org/10.1016/j.matpr.2020.04.124 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the 2nd International Conference on Processing and Characterization of Materials. ⇑ Corresponding author. E-mail address: saikatmandal1992@gmail.com (S. Mandal). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: S. Mandal, A. Pramanick, S. Chakraborty et al., Phase determination of ZrB 2 -B 4 C ceramic composite material using XRD and riet- veld refinement analysis, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.04.124