Effect of ultrasonic field on friction and wear properties of in-situ TiB2/2A14 composite materials

The 3%TiB2 /2A14 (volume fraction) aluminum matrix composites were prepared by in-situ salts-metal reaction under ultrasonic field. The wear experiments with four different load (20, 30, 40, 50N) were carried out with a reciprocating tribometer. The abrasive resistance and friction behavior of composites with different ultrasonic vibration treatment (UVT) process were studied. The mircohardness of matrix and composites were measured by the microhardness tester. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to identify the phase compositions and observe the microstructure and morphology of worn surfaces. And the wear mechanism was also studied. The results manifest that the ultrasonic can efficiently scatter the particle agglomerations, improve the state of particle distribution and reinforce the interfacial bonding strength between particles and matrix. Therefore, the abrasive resistance and microhardness of composites with UVT are obviously superior to alloy matrix. The wear rate and hardness of composites obtained by 120s UVT are about 57.43% and two times of that of the matrix alloy under 50N load. Under the dry friction condition, the main wear mechanism of alloy matrix is adhesion wear and composites is hybrid wear with adhesion wear and abrasive wear and the wear resistance is better.