High strength and damping capacity of LLZNO/Al composites fabricated by accumulative roll bonding

In order to fabricate high damping/strength metal matrix composites, hard ceramic particulates Li6.75La3Zr1.75Nb0.25O12 (LLZNO) reinforced Al composites were prepared by accumulative roll bonding (ARB) method with intermittent heat treatments. LLZNO particles did not react with Al and were uniformly dispersed in Al-matrix after 10 ARB cycles. With increasing ARB cycles, the ultimate tensile strength of the LLZNO/Al composites increased and reached 132 MPa after 10 ARB cycles, which was 2.5 times that of the pure Al, while the total elongation of LLZNO/Al composites increased from 5% after 1 cycle to 10% after 10 cycles. The maximum damping capacity as high as 0.009 was achieved after 10 ARB cycles in the 10 wt% LLZNO/Al composite at 320 K and 1 Hz, which was 4.5 times that of pure Al. The simultaneous enhancement on damping capacity, tensile strength and ductility of the LLZNO/Al composite around room temperature can be ascribed to the high damping capacity and the dispersion strengthening of the LLZNO phase, as well as the good bonding between the LLZNO particles and Al matrix resulted from the ARB technique.