Microstructural tailoring, mechanical and thermal properties of SiC composites fabricated by selective laser sintering and reactive melt infiltration

Abstract

Poor flowability of printable powders and long preparation cycles are the main challenges in selective laser sintering (SLS) of chopped carbon fiber reinforced silicon carbide composites (SiC composites) with complex structures. In this study, we develop an efficient and novel processing route in the fabrication of lightweight SiC composites via SLS of phenolic resin (PR) and Cf powders with the addition of α-SiC particles combined with one-step reactive melt infiltration (RMI). The effects of α-SiC addition on the microstructural evolution of the Cf/SiC/PR printed bodies, Cf/SiC/C green bodies, and derived SiC composites were investigated. The results indicate that the added α-SiC particles play an important role in enhancing the flowability of raw powders, reducing porosity, increasing the reliability of the Cf/SiC/C green bodies, and contributing to improving the microstructure homogeneity and mechanical properties of the SiC composites. The maximum density, flexural strength, and fracture toughness of the SiC composites are 2.749±0.006 g⋅cm −3 , 266±5 MPa, and 3.30±0.06 MPa•m 1/2 , respectively. The coefficient of thermal expansion (CTE) of the SiC composites is approximately 4.29×10 −6 K −1 from room temperature (RT) to 900 °C, and the thermal conductivity is in the range of 80.15-92.48 W•m −1 •K −1 at RT. The high-temperature strength of the SiC composites increase to 287±18 MPa up to 1200 °C. This study provides a novel as well as a feasible tactic for the preparation of high-quality printable powders as well as lightweight, high strength, and high thermal conductivity SiC composites with complex structures by SLS and RMI.

A novel mullite anti-gyroid/SiC gyroid ceramic metastructure based on digital light processing 3D printing with enhanced electromagnetic wave absorption and mechanical properties

“…It's convention to tailor the impedance matching and electromagnetic parameters by regulating the macrostructure of composites for structural EMW-absorbing materials, which have emerged as the major research trend for modern stealth materials in recent years [12,13]. However, it's challenging to fabricate complex structure using traditional processes [14][15][16]. The development of 3D printing technology makes it possible to prepare arbitrary complicated structures and provides new perspective for EMW-absorbing metamaterials.…”

Effect of Particle Grading on Properties of Silicon Carbide Ceramics Prepared by Selective Laser Sintering Printing Combined with Solid-phase Sintering at Atmospheric Pressure

“…Key words: SiC ceramic; particle grading; selective laser sintering printing; solid-phase sintering at atmospheric pressure SiC 陶瓷因具有低密度、高强度、耐高温、耐辐 照、耐腐蚀等优异性能, 成为可在极端环境下应用的 理想候选材料, 在航空航天、装甲、空间光学部件、 核能、化工、半导体等国防与工业重大领域中得到 了广泛应用 [1][2][3] 陶瓷构件 [4][5][6] 。3D 打印有效解决了上述问题, 其在 制备异形构件方面有着天然优势 [7][8][9] 密度低、强度低, 这需要后续热处理工艺来改善 [12] 。 目前热处理的主要方法有反应烧结(LSI) [13] 、化 学气相沉积(CVI) [14] 和前驱体浸渍热解(PIP) [15][16] 。 然而, SLS 打印结合 LSI 会造成游离硅含量高(>10%,…”