原位反应法制备Zr/Hf-ZrC_(1-x)/HfC_(1-x)棒的碳化机制及烧蚀行为  

Carbonization mechanism and ablation behavior of Zr/Hf-ZrC_(1−x)/HfC_(1−x)rods prepared by in-situ reaction method

作　　者：田甜 卿馨 孙威 楚宇昊 TIAN Tian;QING Xin;SUN Wei;CHU Yu-hao(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China)

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2024年第3期679-692,共14页中南大学学报（英文版）

基　　金：Project(CX20220097)supported by the Hunan Graduate Research Innovation Project,China;Project(U19A2099)supported by the National Natural Science Foundation of China;Project(6142906200108)supported by the Fund of Aerospace Research Institute of Material and Processing Technology,China。

摘　　要：采用碳扩散原位反应法制备了Zr/Hf-ZrC_(1-x)/HfC_(1-x)棒,研究了不同的碳化温度和碳源对棒材微观结构和烧蚀行为的影响。研究结果表明,由于HfC和ZrC的无限固溶,在Zr-Hf合金棒中形成了一种双层结构,外层为ZrC/HfC层,内层为含有ZrC_(1-x)/HfC_(1-x)颗粒的Zr/Hf-ZrC_(1-x)/HfC_(1-x)混合层。随着碳化温度的升高,陶瓷层逐渐增厚。当C/C-ZrC-SiC作为碳源时,陶瓷层的厚度明显高于石墨作为碳源时的厚度。烧蚀后,在棒材表面形成一层熔融的ZrO_(2)-HfO_(2)外层,这一氧化层起着对基体表面进行氧化物补偿的作用,在棒材内部形成一层具有低氧透过率的ZrC_(x)O_(y)/HfC_(x)O_(y)层。同时,ZrO_(2)、HfO_(2)及其固溶体颗粒被烧结致密化,从而降低了氧化层的透氧性,并增强了该氧化层的抗烧蚀性。The Zr/Hf-ZrC_(1−x)/HfC_(1−x)rods were prepared by the carbon diffusion in situ reaction.The effects of different carbonization temperatures and carbon sources on the microstructures and the ablative behavior of the rods were investigated.The results show that due to the infinite solution of HfC and ZrC,a two-layer structure was formed in the Zr-Hf alloy rods.The outer layer was ZrC/HfC ceramic layer.The inner was composed of Zr/Hf-ZrC_(1−x)/HfC_(1−x)mixing layer decorated with some isolated ZrC_(1−x)/HfC_(1−x)grains.The thickness of the ceramic layer increased with the increase of carbonization temperature.When C/C-ZrC-SiC was used as the carbon source,the thickness of the ceramic layer was obviously higher than that of graphite used as a carbon source.After ablation,a molten ZrO2-HfO2 outer layer was formed on the rod surface,which acted as an oxide compensation to the substrate surface.The ZrC_(x)O_(y)/HfC_(x)O_(y) layer with a low oxygen diffusion coefficient was formed inside the rod.Meanwhile,ZrO_(2),HfO_(2),and their solid solution particles were sintered and densified,which reduced the oxygen permeability of the oxide layer and enhanced ablation resistance.

关 键 词：碳扩散 陶瓷层 原位反应 耐烧蚀 

分 类 号：TB332[一般工业技术—材料科学与工程]