Elsevier

Ceramics International

Volume 46, Issue 8, Part A, 1 June 2020, Pages 10903-10909
Ceramics International

Mechanical and thermal properties of Graphene nanoplates (GNPs)/Lithium aluminosilicate (LAS) composites: An analysis based on mathematical model and experiments

https://doi.org/10.1016/j.ceramint.2020.01.104Get rights and content

Abstract

The Graphene nanoplates (GNPs)/Lithium aluminosilicate (LAS) glass-ceramic composites were produced by hot-pressing sintering in vacuum condition. The flexural strength, fracture toughness, and thermal conductivity of the composites with different GNPs contents were investigated. The flexural strength and thermal conductivity reached maximum (137.17Ā Ā±Ā 6.50Ā MPa and 1.98Ā WĀ·māˆ’1Ā·Kāˆ’1) when the content of GNPs increased to 2Ā wt%. When the GNPs content reached 3Ā wt%, fracture toughness reached maximum (5.45Ā Ā±Ā 0.20Ā MPaĀ·m1/2), which has obvious improvement compared with pure LAS glass-ceramic (1ā€“2Ā MPaĀ·m1/2). The mathematical models were induced to further investigate the effects of the agglomeration and content of GNPs on mechanical and thermal properties of the composite. The results show that the agglomeration of GNPs weakens the mechanical properties of the composites by reducing the energy dissipation of GNPs pull-out. The interfacial thermal resistance between the GNPs and LAS decreases initially followed by increasing, which will affect the thermal conductivity of the composites. This new material system will further expand the field of LAS ceramics in the future.

Introduction

Currently, with the rapid development of information technology, lithium aluminosilicate (LAS) glass-ceramic has attracted a lot of attention in the past few years due to their superior wave-transparent properties [[1], [2], [3], [4]]. Besides, LAS glass-ceramic also has good thermal properties, such as ultra-low coefficient of thermal expansion, and great thermal shock resistance [[5], [6], [7]], demonstrating attractive application in aerospace and communications. However, their wide application as structure materials was hindered by the low toughness and strength like most ceramics. Thus, the fibers [5,[7], [8], [9], [10]], nanotubes [[11], [12], [13], [14]], and whiskers [13] are often used as an enhanced phase to improve the mechanical properties of ceramic.

Graphene has attracted wide attention since its discovery owing to the excellent properties that include high fracture strength, high Young's modulus, high thermal conductivity, excellent charge-carrier mobility, and so on [[15], [16], [17], [18]]. Graphene has two-dimensional structure and produces almost no stress concentration due to its smaller size compared with fibers and whiskers. However, single-layered graphene is hard to obtain [[19], [20], [21]]. Graphene nanoplates (GNPs) are consisted of several layers of graphene and have similar properties to single-layer graphene. Besides, GNPs are much easier to produce. Thus, GNPs are ideal substitute of graphene and GNPs reinforced ceramic composites were paid wide attention by researchers [22,23].

In last few years, GNPs/ceramic composites have been focused by researchers, such as GNPs/Si3N4 [[24], [25], [26], [27]], GNPs/Al2O3 [[28], [29], [30], [31], [32], [33], [34], [35], [36], [37]], GNPs/ZrO2 [38], and so on [32,[39], [40], [41], [42]]. The fracture toughness of the composites can be improved through crack branching, deflection and bridging with the addition of GNPs [43]. The thermal conductivity is mainly controlled by the anisotropy of GNPs which have low through-plane thermal conductivity and high in-plane thermal conductivity [44].

In this study, GNPs were induced to improve the mechanical properties of LAS glass ceramic for the first time, and the GNPs/LAS composites were produced by hot-pressing sintering in vacuum condition. The phases in the composite are identified by XRD pattern and FTIR spectral. The flexural strength, fracture toughness and thermal conductivity of the composites with different GNPs contents were measured. By using mathematical models, the effect of GNPs content on the mechanical and thermal properties have been investigated in detail.

Section snippets

Experimental

LAS precursor powder and GNPs are used as the raw materials. The GNPs are dispersed in alcohol firstly as shown in Fig. 1. Then LAS powder is added to these slurries with GNPs ratios of 1ā€“4Ā wt% (named G-1, G-2, G-3, G-4) and 5Ā wt% methylcellulose (based on LAS precursor powders) is used as the dispersant. Next, the mixture is ball-milled in alcohol at 550Ā rpm for 3Ā h and dried for 24Ā h. The dried mixture powder is sieved using an 80 mesh. Finally, the GNPs/LAS are obtained by using vacuum

Characterization and microstructure

Fig. 2a shows the XRD patterns of the GNPs/LAS ceramic composites. The spectra of different specimens are similar [45,46]. The peaks of the sintered GNPs/LAS are well matched to LiAlSi3O8 (PDF#35ā€“0794). Fig. 2b shows the FTIR spectra of the composites. The peak at ~990Ā cmāˆ’1 corresponds to the telescopic asymmetric vibration of Siā€“O band; the peak at ~740Ā cmāˆ’1 relates to the symmetric vibration of Siā€“Oā€“Al band. Besides, the peaks of GNPs are not detected by XRD and FTIR due to its small quantity.

Conclusions

The GNPs reinforced LAS glass-ceramic composites were fabricated by means of hot-press sintering method at 1200Ā Ā°C for 0.5Ā h. The main phase in the products is LiAlSi3O8 identified by XRD pattern and FTIR spectra. The dispersion of GNPs decreases with the addition of GNPs content (2ā€“4Ā wt%) by analyzing the IG/IGā€™ of Raman spectra combined with the microstructure of specimens. The flexural strength and thermal conductivity increase first and then decrease with the increase of GNPs content.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant No. 51621091, 51872058, 51772060 and 51972078), Key Laboratory of Advanced Structural-Functional Integration Materials & Green Manufacturing Technology, Harbin Institute of Technology, Harbin, 150001, China.

References (54)

  • X. Zhao et al.

    Synthesis and theoretical study of large-sized Bi4Ti3O12 square nanosheets with high photocatalytic activity

    Mater. Res. Bull.

    (2018)
  • W. Guo et al.

    The microstructure and mechanical properties of C/C composite/Ti3Al alloy brazed joint with graphene nanoplatelet strengthened Ag-Cu-Ti filler

    Ceram. Int.

    (2019)
  • W. Zhang et al.

    Structure-microwave absorption performance correlations of GNPs/ZnO nanocomposite absorber: synthesis, characterisation and mechanism investigation

    Ceram. Int.

    (2019)
  • C. Ramirez et al.

    Extraordinary toughening enhancement and flexural strength in Si3N4 composites using graphene sheets

    J. Eur. Ceram. Soc.

    (2014)
  • P. Hvizdos et al.

    Tribological properties of Si3N4-graphene nanocomposites

    J. Eur. Ceram. Soc.

    (2013)
  • C. Ramirez et al.

    Graphene nanoplatelet/silicon nitride composites with high electrical conductivity

    Carbon

    (2012)
  • L. Kvetkova et al.

    Fracture toughness and toughening mechanisms in graphene platelet reinforced Si3N4 composites

    Scr. Mater.

    (2012)
  • Y. Cheng et al.

    Mechanical properties and toughening mechanisms of graphene platelets reinforced Al2O3/TiC composite ceramic tool materials by microwave sintering

    Mater. Sci. Eng.

    (2017)
  • W. Wu et al.

    The reinforcing effect of graphene nano-platelets on the cryogenic mechanical properties of GNPs/Al2O3 composites

    J. Alloy. Comp.

    (2017)
  • Y. Fan et al.

    The effect of homogeneously dispersed few-layer graphene on microstructure and mechanical properties of Al2O3 nanocomposites

    J. Eur. Ceram. Soc.

    (2014)
  • Y. Fan et al.

    Preparation and electrical properties of graphene nanosheet/Al2O3 composites

    Carbon

    (2010)
  • J. Sun et al.

    Determination of microstructure and mechanical properties of functionally graded WC-TiC-Al2O3-GNPS micro-nano composite tool materials via two-step sintering

    Ceram. Int.

    (2017)
  • X. Meng et al.

    Microstructure and anisotropy of mechanical properties of graphene nanoplate toughened Al2O3-based ceramic composites

    Ceram. Int.

    (2016)
  • E. Cui et al.

    Microstructure and toughening mechanisms of Al2O3/(W, Ti)C/graphene composite ceramic tool material

    Ceram. Int.

    (2018)
  • X. Feng et al.

    Graphene promoted oxygen vacancies in perovskite for enhanced thermoelectric properties

    Carbon

    (2017)
  • Y. Fan et al.

    Highly strain tolerant and tough ceramic composite by incorporation of graphene

    Carbon

    (2015)
  • Y. Yan et al.

    Enhanced photocatalytic activity of surface disorder-engineered CaTiO3

    Mater. Res. Bull.

    (2018)
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