Fabrication and microstructure evolution of Csf/ZrB2-SiC composites via direct ink writing and reactive melt infiltration

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.

“…The orientation distribution and 'Hermans' orientation parameter (fp) of the Cf in the Cf/SiC/C green body were determined using the following equations [19]:…”

Section: Fabrication Of Sic Compositesmentioning

confidence: 99%

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

Xiao¹,

Yin²,

Huang³

et al. 2023

“…Moreover, with the tape casting, only a low amount of fibres (10-15 vol%) can be added [34]. Recently, the inks based on ZrB 2 and short fibres have been prepared by three-dimensional (3D) printing [35,36]. This technique offers the possibility of creating near-net-shaped components with a controlled fibre alignment [37].…”

Section: Introduction mentioning

confidence: 99%

A novel approach for manufacturing of layered, ultra-refractory composites using pliable, short fibre-reinforced ceramic sheets

MOR¹,

Vinci²,

Failla³

et al. 2023

A new additive technique for manufacturing of short fibre-reinforced ultra-refractory ceramics is presented. This technique allows the fabrication of solvent-free, thin (~100 µm), flexible, and easy-to-handle sheets suitable for fabricating homogeneous or layered structures. A large range of compositions, in terms of matrix and fibre volumetric contents, from 0% to 100% is possible. The amount of short carbon fibres incorporated in the sheets ranged from 20 to 50 vol%, whereas the fibre length ranged from 3 to 5 mm. The matrix composition investigated with this technique consisted of ZrB 2 /SiC/Y 2 O 3 . By increasing the fibre amount from 35 to 50 vol%, an improvement of mechanical properties was observed. Four-point flexural strength (σ) ranged from 107 to 140 MPa, depending on the amount of carbon fibres (C f ). The same holds true for the work of fracture, ranging from 108 to 253 J/m 2 . Functionally graded composites were fabricated by overlapping sheets with a fibre gradient (0%-50%).

“…When hypersonic vehicle travels back to the atmosphere, reply the demanding thermal-protection requirements [5][6][7][8]. However, due to the crack sensitivity and lower strain tolerance of single-component UHTCs [9,10], toughening phases need to be used to improve the fracture toughness in practical application [11][12][13][14]. Among them, carbon fiber (CF) is considered to be a material that is expected to fundamentally solve the brittleness of ceramics by bridging mechanism and crack deflection, so that the energy applied to the composite material can be slowly released to improve the fracture toughness of the composite material [15][16][17][18][19].…”

Section: Introduction mentioning

confidence: 99%

ZrB ₂–SiC spiral fibers prepared by combining liquid rope effect with non-solvent-induced phase separation method: A promising toughening material for ultra-high temperature ceramics

ZHANG¹,

Guo²,

Xing³

et al. 2023

Spiral fibers were considered to be an ideal toughening phase of ultra-high torsional release effect. In this work, ZrB 2 (Z)-20 vol% SiC (S) spiral fiber (ZS sf ) with controllable structure was prepared by a combination approach of liquid rope effect and non-solvent-induced phase separation. Dominantly depended on the kinematic viscosity (η), dropping height (H), and flow rate (Q), the geometric parameters of ZS sf involving filament diameter (d) and coil diameter (D) were followed the relationship of d ≈ 0.516×10 −3 Q 1/2 H −1/4 and D ≈ 0.25×10 -3 (Q/H) 1/3 , respectively, within the optimized η of 10-15 Pa•s. Three different microstructures of ZS sf were achieved by adjusting the polymer/solvent/ non-solvent system assisted with phase diagram calculation, including dense, hollow, and hierarchical pore structures. The ZrB 2 -SiC with 1 wt% ZS sf composites prepared by hot isostatic pressing (HIP) exhibited a ~30% increase in fracture toughness (K IC , 4.41 MPa•m 1/2 ) compared with the ZrB 2 -SiC composite, where the microscopic fracture toughness of the ZS sf was ~80% higher than that of the matrix. The fibers with a ~10 nm in-situ-synthesized graphite phase amongst grain boundaries of ZrB 2 and SiC changed the fracture mode, and promoted the crack deflection and pull-out adjacent the interface of matrix and the fiber.