New bulk MAX phase-based ceramics were synthesized in the Ta–Hf–Al–C and Ta–Nb–Al–C systems. Specifically, (Ta_1-x,Hf_x)₄AlC₃ and (Ta_1-x,Nb_x)₄AlC₃ stoichiometries with x = 0.05, 0.1, 0.15, 0.2, 0.25 were targeted by reactive hot pressing of Ta₂H, HfH₂, NbH_0.89, Al and C powder mixtures at 1550 °C in vacuum. The produced ceramics were characterized in terms of phase composition and microstructure by X-ray diffraction, scanning electron microscopy, electron probe microanalysis and scanning transmission electron microscopy. The investigation confirmed the existence of such M-site solid solutions with low solute concentrations, as predicted by first-principles calculations. These calculations also predicted a linear trend in lattice parameter evolution with increasing Hf concentration, in agreement with the experimental results. In order to increase the low phase purity of the produced ceramics, Sn was added to form (Ta_1-x,Hf_x)₄(Al_0.5,Sn_0.5)C₃ and (Ta_1-x,Nb_x)₄(Al_0.5,Sn_0.5)C₃ double solid solutions, thus resulting in a higher content of the 413 MAX phase compounds in the produced ceramics.

在Ta–Hf–Al–C和Ta–Nb–Al–C系统中合成了新的基于MAX相的块状陶瓷。具体而言，通过Ta ₂ H的反应热压，以（Ta _1-x，Hf _x）₄ AlC ₃和（Ta _1-x，Nb _x）₄ AlC _3的化学计量比为x = 0.05、0.1、0.15、0.2、0.25。，HfH ₂，NbH _0.89，Al和C的粉末混合物在1550°C的真空中。通过X射线衍射，扫描电子显微镜，电子探针显微分析和扫描透射电子显微镜，在相组成和微观结构方面表征了所制造的陶瓷。正如第一性原理计算所预测的那样，研究证实了这种具有低溶质浓度的M位固溶体的存在。这些计算还预测了随着Hf浓度的增加，晶格参数演化的线性趋势，与实验结果一致。为了提高所生产陶瓷的低相纯度，添加了Sn以形成（Ta _1-x，Hf _x）₄（Al _0.5，Sn _0.5）C _3。和（Ta _1-x，Nb _x）₄（Al _0.5，Sn _0.5）C ₃双重固溶体，因此在所生产的陶瓷中导致413 MAX相化合物的含量更高。