Abstract

In this research V₄AlC₃ based composites were synthesized by reactive spark plasma sintering (RSPS) method. V₂O₅:Al:C starting materials with molar ratios of 1:6:1.5 and 1:7:1.5 were heat treated at 1400 °C. Final composition, microstructural, physical, mechanical and tribological properties of the prepared composites were compared. The X-ray diffraction analysis results showed that the formation of V₄AlC₃ as main phase alongside Al₂O₃ and V₂AlC by-products. Increasing the Al content from 6 moles to 7 moles led to formation of VC_0.845 and Al₂O₃ main phases as well as V₄AlC₃ and V₂AlC minor phases in this sample due to extraction of Al from die during RSPS operation. Microstructural studies revealed that the uniform distribution of the phases with low amount of porosities. The layered microstructure of the composites confirmed the formation of MAX phases. Higher bending strength and is achieved for the synthesized composite prepared by 7 moles Al (490 ± 5 MPa) than the composite prepared with 6 moles Al (375 ± 11 MPa). The composite prepared with 7 moles Al also exhibited lower wear rate (3.7 × 10^− 5 mm³/Nm) than that of prepared with 6 moles Al (2.4 × 10^− 4 mm³/Nm). Microstructural studies of the worn surfaces indicated that tribo oxidation is dominant mechanism for both fabricated composites.

Graphic Abstract

中文翻译：

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V 2 O 5：Al：C的反应放电等离子烧结合成V 4 AlC 3基MAX相复合材料

摘要

在这项研究中，通过反应火花等离子体烧结（RSPS）方法合成了基于V ₄ AlC ₃的复合材料。摩尔比为1：6：1.5和1：7：1.5的V ₂ O ₅：Al：C原材料在1400°C进行了热处理。比较了所制备复合材料的最终组成，微观结构，物理，机械和摩擦学性能。X射线衍射分析结果表明，与Al ₂ O ₃和V ₂ AlC副产物一起形成了以V ₄ AlC ₃为主要相。Al含量从6摩尔增加到7摩尔导致形成VC _0.845和Al ₂ O此样品中的_3个主要相以及V ₄ AlC ₃和V ₂ AlC次要相，这是由于在RSPS操作过程中从模具中提取了Al。显微组织研究表明，相的分布均匀，孔隙率低。复合材料的层状微观结构证实了MAX相的形成。与由6摩尔Al（375±11 MPa）制备的复合材料相比，由7摩尔Al（490±5 MPa）制备的合成复合材料具有更高的弯曲强度。复合与7个摩尔的Al也表现出较低的磨损率（3.7×10制备^-第5毫米³ / Nm）的比的与6个摩尔的Al（2.4×10制备^-第4毫米³/ Nm）。磨损表面的微观结构研究表明，摩擦氧化是两种复合材料的主要机理。

图形摘要