Tribological properties of aluminum alloy matrix TiB2 composite prepared by in situ processing

Abstract

An investigation of the wear behavior, in lubricated sliding and rolling of in situ prepared TiB 2 particle-reinforced 2024 T4 Al alloy matrix composites against 52100 steel and hardened pearlitic nodular cast iron, respectively, was undertaken. In sliding contact, the 10 vol pct 0.3-m TiB 2 -metal matrix composite (MMC) showed slightly less wear than the 10 vol pct 1.3-m TiB 2 -MMC. Transmission electron microscopy of cross sections, taken normal to the wear track and parallel to the sliding direction, revealed that the TiB 2 particles on the wear track were polished and particle pullout was largely absent. This was attributed to the strong interfacial bonding between the Al-alloy matrix and the TiB 2 reinforcing phase. The TiB 2 particles on the wear track inhibited spalling. Subsurface damage of the MMC did not occur. The wear of the steel mating surfaces worn against the TiB 2 -MMCs was minor and caused by the cutting action of the TiB 2 particles that resided on the MMC wear track. In rolling contact, the 0.3-m-size TiB 2 -MMC showed 5 times higher weight loss than the 1.3-m TiB 2 -MMC for the same content of reinforcement, but the weight loss of the cast iron mating surface was less for the former. For the smaller particle size, the wear of 5 and 10 vol pct TiB 2 -MMCs was the same. A high density of surface cracks was present on the wear track of the 0.3-m TiB 2 -MMC but not on the 1.3-m MMC. The significance of strong particle/matrix interfacial bonding and particle size effect on the wear behavior of ceramic particulate-reinforced MMCs in lubricated sliding and rolling wear is discussed.

Effect of age-hardening on dry sliding wear behavior of mushy state rolled in-situ Al-4.5Cu-5TiB2 composites

“…Moreover, earlier reports have shown that addition of TiB 2 as reinforcement significantly enhances the wear resistance of the composite compared to that of the monolithic alloy [19][20][21][22][23][24][25][26][27]. The superior wear resistance found in case of the in-situ Al-TiB 2 composite has been attributed to strong particle-matrix interfacial bond in this material [23,24].…”

“…This causes an increase in dislocation density in the matrix of the Al-MMCs, leading to significant strengthening [11][12][13] as well as enhancement of aging kinetics [14][15][16][17][18]. Moreover, earlier reports have shown that addition of TiB 2 as reinforcement significantly enhances the wear resistance of the composite compared to that of the monolithic alloy [19][20][21][22][23][24][25][26][27]. The superior wear resistance found in case of the in-situ Al-TiB 2 composite has been attributed to strong particle-matrix interfacial bond in this material [23,24].…”

Wear Behaviour of Squeeze-Cast Al 2014 Alloy and <i>In-Situ</i> 5 vol% TiB₂/2014 Composite

“…However, compared with the gravity-cast composite, improvement in wear resistance of the squeeze-cast composite is attributed to not only increase in hardness and reduction in casting defects but also improved dispersion of TiB 2 particles during squeeze casting. The earlier reports 32,33) have indicated the wear mechanism of AlTiB 2 composite. It is proposed that the aluminium matrix surrounding the particles is worn away preferentially in the initial stages under sliding wear conditions, leaving the reinforcing particles in contact with the steel counterface.…”

Wear behaviour of near eutectic Al–Si alloy reinforced with in-situ TiB2 particles

“…Most of the work pertaining to wear behaviour of MMCs has been carried out with SiC as the reinforcing medium, particularly in the hypoeutectic Al-Si system [2][3][4], though a few others have investigated the sliding wear behaviour in eutectic systems [9]. Although some wear studies on Al alloys reinforced with in-situ TiB 2 particles has been carried out [1,5,[10][11][12][13], very few literature have focused on the effect of in-situ TiB 2 particles in eutectic Al-Si alloy [13]. The above investigators have attributed the beneficial effect of insitu TiB 2 particles to the clean particle-matrix interface in such MMCs.…”

“…The above investigators have attributed the beneficial effect of insitu TiB 2 particles to the clean particle-matrix interface in such MMCs. However none of the reports have elucidated the effect of wear debris size and the role of transfer layers towards the wear behaviour, though a few wear mechanisms have been proposed earlier [10,11].…”