The transverse rupture strength (TRS) is a key mechanical property for brittle Ti(C,N)-based cermets. However, the complicated structure with the ceramics hard phase and the metal binder phase makes it challenging to ascertain the essential impact on the TRS. To fundamentally understand the fracture in this system, herein, we present a theoretical model to investigate the essential TRS including friction stress at the phase boundary and Peierls stress of dislocations based on the first-principles method, in which the strain-stress method and Peierls-Nabarro method are employed. The traditional application of this method is analyzing the contributions to the yield strength (YS) in the constitution equation. In this article, we present a transformation of the TRS calculation into YS calculation in terms of some basic mechanical theories, thereby extending the applicability of this method to the calculation of TRS. And, the numerical valuations with good linear fit between the experimental TRS and calculated TRS including intrinsic strength, Hall-Petch effect, as well as dislocation density hardening provide solid evidence for the accuracy of our deductions and theoretical model. Finally, it is evident that the brittle components in cermets are not typically the ceramic phase itself. Our methodology illuminates a novel yet effective approach for analyzing fracture in Ti(C,N)-based cermets, which may be extended to other brittle materials in future.

中文翻译：

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根据脆性 Ti（C，N） 基金属陶瓷的 ab-initio 方法计算的真实横向断裂强度


横向断裂强度 （TRS） 是脆性 Ti（C，N） 基金属陶瓷的关键机械性能。然而，陶瓷硬质相和金属粘结剂相的复杂结构使得确定对 TRS 的本质影响变得具有挑战性。为了从根本上理解该系统中的断裂，本文提出了一个理论模型来研究基本的 TRS，包括相边界的摩擦应力和基于第一性原理方法的位错的 Peierls 应力，其中采用了应变-应力法和 Peierls-Nabarro 方法。这种方法的传统应用是分析结构方程中对屈服强度 （YS） 的贡献。在本文中，我们从一些基本的力学理论的角度介绍了 TRS 计算到 YS 计算的转换，从而将该方法的适用性扩展到 TRS 的计算中。而且，实验 TRS 和计算的 TRS 之间具有良好的线性拟合的数值评估，包括内禀强度、Hall-Petch 效应以及位错密度硬化，为我们的推导和理论模型的准确性提供了坚实的证据。最后，很明显，金属陶瓷中的脆性成分通常不是陶瓷相本身。我们的方法阐明了一种新颖而有效的方法来分析 Ti（C，N） 基金属陶瓷的断裂，将来可能会扩展到其他脆性材料。