Ablation-resistant carbide Zr0.8Ti0.2C0.74B0.26 for oxidizing environments up to 3,000 degrees C
Ablation-resistant carbide Zr0.8Ti0.2C0.74B0.26 for oxidizing environments up to 3,000 degrees C
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耐烧蚀硬质合金 Zr0.8Ti0.2C0.74B0.26 适用于高达 3,000 摄氏度的氧化环境
DOI：
10.1038/ncomms15836
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发表时间：
2017
影响因子：
16.6
通讯作者：
Xiao Ping
中科院分区：
文献类型：
--
作者：
Zeng Yi;Wang Dini;Xiong Xiang;Zhang Xun;Withers Philip J.;Sun Wei;Smith Matthew;Bai Mingwen;Xiao Ping
超高温陶瓷在高超声速飞行器、火箭、再入航天器和国防领域的应用是理想的，但目前很少有材料能满足相关的高温烧蚀要求。本文采用反应熔融渗透和填充胶结的方法，在C/C复合材料上设计并制备了硬质合金（Zr0.8Ti0.2C0.74B0.26）涂层。与现有的超高温陶瓷相比，它在2000 - 3000°C的温度下显示出卓越的抗烧蚀性（例如，在2500°C时，材料损失率是传统碳化锆的12倍以上）。碳化物是一种含有硼原子随机占据的碳空位的Zr-Ti取代固溶体。陶瓷氧化物的密封能力、缓慢的氧扩散和致密的梯度分布使得在烧蚀过程中形成的保护氧化层的损失比其他陶瓷体系要慢得多，从而具有更好的抗烧蚀性。
Ultra-high temperature ceramics are desirable for applications in the hypersonic vehicle, rockets, re-entry spacecraft and defence sectors, but few materials can currently satisfy the associated high temperature ablation requirements. Here we design and fabricate a carbide (Zr0.8Ti0.2C0.74B0.26) coating by reactive melt infiltration and pack cementation onto a C/C composite. It displays superior ablation resistance at temperatures from 2,000–3,000 °C, compared to existing ultra-high temperature ceramics (for example, a rate of material loss over 12 times better than conventional zirconium carbide at 2,500 °C). The carbide is a substitutional solid solution of Zr–Ti containing carbon vacancies that are randomly occupied by boron atoms. The sealing ability of the ceramic’s oxides, slow oxygen diffusion and a dense and gradient distribution of ceramic result in much slower loss of protective oxide layers formed during ablation than other ceramic systems, leading to the superior ablation resistance.