Microstructure and mechanical properties of Zr3Al3C5-based ceramics synthesized by Al-Si melt infiltration

Xiaomeng Fan,Laifei Cheng,Jinxue Ding,Yangfang Deng,Yuzhao Ma

doi:10.1007/s40145-020-0455-9

Xiaomeng Fan, Laifei Cheng + Show 3 more

Open Access

https://doi.org/10.1007/s40145-020-0455-9

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Abstract

In this work, bulk Zr3Al3C5-based ceramics were synthesized by the infiltration of Al-Si melt into zirconium carbide (ZrC) perform. The phase composition, microstructure, and mechanical properties of as-fabricated ceramics were studied. The results demonstrate that Si is more effective to reduce the twin boundary energy of ZrC than Al, and thus promotes the decrease of formation temperature of Zr3Al3C5. With the infiltration temperatures increasing from 1200 to 1500 °C, the Zr3Al3C5 content increases from 10 to 49 vol%, which is contributed to the increase of flexural strength from 62±9 to 222±10 MPa, and fracture toughness (KIC) from 2.8±0.2 to 4.1±0.3 MPa·m1/2. The decrease of mechanical properties for the samples fabricated at 1600 °C is ascribed to the abnormal growth of Zr3Al3C5 grains.

Highlights

Ultra-high-temperature ceramics (UHTCs), a group of advanced structural ceramics, exhibit indispensable advantages in ultra-high-temperature service environment for the thermal protection system of hypersonic vehicles [1,2]
The resultant is mainly composed of zirconium carbide (ZrC) and few ZrAl3 after reaction under 1400 °C, and Zr3Al3C5 started to precipitate with the infiltration temperature increasing to 1500 °C
Zr3Al3C5 can be formed at 1200 °C for Al–Si melt infiltration, whereas it needs a higher temperature for Al melt infiltration, which demonstrates that Si plays a more effective role in reducing the TBE of ZrC than Al

Summary

Introduction

Ultra-high-temperature ceramics (UHTCs), a group of advanced structural ceramics, exhibit indispensable advantages in ultra-high-temperature service environment for the thermal protection system of hypersonic vehicles [1,2]. J Adv Ceram 2021, 10(3): 529–536 can be formed to inhibit the inward-diffusion of oxygen effectively, resulting in better oxidation resistance than binary carbides [8,9] These ternary carbides are treated as novel promising high-temperature structural materials. Compared with the above mentioned methods, reactive melt infiltration (RMI) is one of the most effective ways to fabricate bulk ceramics with complex shape [11,12]. It is rarely seen the report on the synthesis of bulk Zr3Al3C5-based ceramics by RMI. The role of Si in the formation of Zr3Al3C5 was revealed, and the microstructure and mechanical properties of bulk ceramics fabricated at different infiltration temperatures were discussed

Experimental

Results and discussion

Conclusions