"Diffusion-controlled alloying of single-phase multi-principal transition metal carbides with high toughness and low thermal diffusivity"

Chong Peng: Xiang Gao, Mingzhi Wang, Lailei Wu, Hu Tang, Xiaomin Li, Qian Zhang, Yang Ren, Fuxiang Zhang, Yuhui Wang, Bing Zhang, Bo Gao, Qin Zou, Yucheng Zhao, Qian Yang, Dongxia Tian, Hong Xiao, Huiyang Gou, Wenge Yang, Xuedong Bai, Wendy L. Mao, and Ho-kwang Mao; Applied Physics Letters, 01/08/2019.

Additional Authors: Xiang Gao, Mingzhi Wang, Lailei Wu, Hu Tang, Xiaomin Li, Qian Zhang, Yang Ren, Fuxiang Zhang, Yuhui Wang, Bing Zhang, Bo Gao, Qin Zou, Yucheng Zhao, Qian Yang, Dongxia Tian, Hong Xiao, Huiyang Gou, Wenge Yang, Xuedong Bai, Wendy L. Mao, and Ho-kwang Mao

Abstract:

Multicomponent alloying has displayed extraordinary potential for producing exceptional structural and functional materials. However, the synthesis of single-phase, multi-principal covalent compounds remains a challenge. Here, we present a diffusioncontrolled alloying strategy for the realization of covalent multi-principal transition metal carbides (MPTMCs) with a single facecentered cubic phase. The increased interfacial diffusion promoted by the addition of a nonstoichiometric compound leads to rapid formation of the single phase at much lower sintering temperature. Direct atomic-level observations via scanning transmission electron microscopy demonstrate that MPTMCs are composed of a single phase with a random distribution of all cations, which holds the key to the unique combinations of improved fracture toughness, superior Vickers hardness, and extremely lower thermal diffusivity achieved in MPTMCs. The present discovery provides a promising approach toward the design and synthesis of next-generation high-performance materials.