Strength and fracture toughness of short‐carbon‐fiber/hafnium‐carbide composites

Abstract

Carbon‐fiber/hafnium‐carbide‐matrix composite specimens were obtained by hot pressing technique. The microstructure of the composites does not reveal chemical interactions between the fiber and matrix. The dependences of strength σ* and critical stress intensity factor K* of composites on fiber volume fraction Vf have maximums. The values of Vf for maximums of σ* and K* are of about 0.06 and ~0.12, respectively. The mean values of these characteristics are ~340 MPa and ~8.7 MPa∙m½. The same characteristics for the matrix obtained at the same technological regime are 250 MPa and 4.9 MPa∙m½.

Preparation and ablation resistance of carbon fiber with yttrium silicate coating

“…Carbon fibers are highly desirable for engineering applications due to their exceptionally high strength and Young's modulus, as well as their low density and coefficient of thermal expansion 1,2 . Carbon fiber‐reinforced materials, such as carbon/carbon and carbon/phenolic composites, are usually selected as thermal protection materials for aerospace vehicles 3–5 .…”

Effect of slurry and sol‐gel introduce SiCnws on ablation and bending behaviors of modified SiCf/HfC‐SiC composites

“…Among them, hafnium carbide (HfC) possesses the highest melting point, good ablation resistance, and phase stability 19–22 . Meanwhile, HfO 2 , the oxidation product of HfC, not only possesses a high melting point but also exhibits low saturated vapor pressure at high temperatures 23–25 . Yan et al 26 .…”

“…[19][20][21][22] Meanwhile, HfO 2 , the oxidation product of HfC, not only possesses a high melting point but also exhibits low saturated vapor pressure at high temperatures. [23][24][25] Yan et al 26 modified C f /SiC composites by adding the HfC ceramics. The mass loss and erosion depth of C f /HfC-SiC composites (0.602 g and 0.472 mm, respectively) were lesser than that of C f /SiC composites (2.322 g and 3.402 mm, respectively).…”