Tough salami-inspired Cf/ZrB2 UHTCMCs produced by electrophoretic deposition

Abstract

One of the biggest challenges of the materials science is the mutual exclusion of strength and toughness. This issue was minimized by mimicking the natural structural materials. To date, few efforts were done regarding materials that should be used in harsh environments. In this work we present novel continuous carbon fiber reinforced ultra-high-temperature ceramic matrix composites (UHTCMCs) for aerospace featuring optimized fiber/matrix interfaces and fibers distribution. The microstructures-produced by electrophoretic deposition of ZrB 2 on unidirectional carbon fibers followed by ZrB 2 infiltration and hot pressing-show a maximum flexural strength and fracture toughness of 330 MPa and 14 MPa m 1/2 , respectively. Fracture surfaces are investigated to understand the mechanisms that affect strength and toughness. The EPD technique allows the achievement of a peculiar salami-inspired architecture alternating strong and weak interfaces.

Ab-initio modeling and experimental investigation of properties of ultra-high temperature solid solutions TaxZr1-xC

“…Refractory compounds of transitional metals (Ta, Nb, Ti, Zr, Hf) usually serve as the basis for UHTCs [5]. Potential applications of UHTCs include hightemperature solar concentrators for renewable energy industry, barrier coatings, hard coatings [6][7][8][9]. TaC (Tm=3950°С) and ZrC (Tm=3420 °С) are among the most refractory compounds known today [10][11][12].…”

Selection, processing, properties and applications of ultra-high temperature ceramic matrix composites, UHTCMCs – a review

“…1) The continuous fibrous reinforcement is coated with interphase layers, typically pyrolytic carbon [276] or ceramic [275], [277] to enhance the fracture toughness of the composite and protect the fibres during pressing.…”

“…However, as discussed by Zoli et al [281], despite the formation of brittle phases, pull-out still occurs because of the onion-like structure of the carbon fibres. It has also been reported that other mechanisms of toughening are activated, either crack deflection [275] or, in weak matrix composites such as porous Cf-ZrB2 [279] , with a fracture mechanism similar to that which occurs in oxide-oxide CMCs [282]. Table 9 [275], [276], [278], [279], [281], [283] summarises the thermomechanical behaviour achieved by hot pressed UHTCMCs, including microstructural and physical properties.…”

“…Table 9 Mechanical properties, density achieved and sintering conditions of UHTCMCs processed by hot pressing [275], [276], [278], [279], [281], [283] Table 10 Properties of carbon fibre reinforced ultra-high temperature ceramic matrix composites prepared by different approaches [179], [192], [227], [279], [281], [294]- [296], [306]- [308].…”

Introduction to H2020 project C3HARME – next generation ceramic composites for combustion harsh environment and space

“…Depending on the precursors used, the composition of the infiltrated samples varied in the amount of ZrC and ZrB 2 [25]. Finally, both SiC f and C f /ZrB 2 UHTCMCs, coupling conventional impregnation techniques with sintering by hot pressing were recently fabricated [26][27][28][29][30][31].…”