Nacre-inspired Ti (C, N)/Al–Cu composites with high damage tolerance and wear resistance prepared by freeze and squeeze casting

Abstract

Freeze casting is an attractive method for designing lamellar ceramic-aluminum composites with a unique combination of strength and toughness. However, there are few studies on the detailed mechanical properties, especially wear resistance, of lamellar Ti(C,N)/Al–Cu composites. Herein, nacre-inspired Ti(C,N)/Al–Cu composites are fabricated via freeze and squeeze casting, and their mechanical and frictional wear properties are investigated. The results show that compressive strength, bending strength, crack-initiation toughness (KIC), and crack-growth toughness (KJC) of composites are 769.2–996.8 MPa, 547.8 MPa, 13.9 MPa m1/2, and 31.1 MPa m1/2, respectively. The achieved strength and toughness are higher than those of most nacre-inspired ceramic/Al composites. The high damage tolerance is affected by interface binding strength between Ti(C,N) and Al, as well as multiple mechanisms. Moreover, friction and wear properties of composites exhibit obvious anisotropy and the transverse section, i.e., perpendicular to freeze direction, exhibits the best wear resistance with a wear rate of only 0.98 × 10−4 mm3/Nm. This anisotropy can be attributed to the different arrangements of ceramic layers on the different sections, which affects their bearing capacity.

Keywords

• Freeze casting
• Squeeze casting
• Ti(C,N)/Al–Cu composites
• Fracture behavior
• Frictional wear mechanism