Hardness improvement of Pb75% - Sb15% - Sn10% bearing alloy through reinforcement with 5% v/v SiO2 particulates

Abstract

The work ‘Hardness Improvement of Pb75%-Sb15%-Sn10% Bearing Alloy through Reinforcement with 5% v/v SiO2 Particulates’ has been carried out. The research involved the development of the composite. The alloy matrix which was earlier developed in the foundry shop of NMDC was used for the production of the composite through the stir cast method. The bars were prepared into test specimens some of them were solution treated, age-hardened and then they were subjected to hardness test and microstructural examination. The result of the work revealed that the as cast sample had a hardness value of 34 HRB and showed improvement when compared with the hardness value of the matrix alloy used for the development of the composite which had a hardness value of 27.7 HRB. The highest value of 35 HRB occurred after 3 hrs of age-hardening the composite. The microstructural analysis confirmed the changes in the hardness values as it revealed the constituent phases of the composite at different ageing periods. The microstructure also agreed with revelations from Scanning Electron Microscope (SEM) images captured on similar alloys. The improved hardness recorded with the reinforcement of Pb75%-Sb15%-Sn10%alloy with particulate silica clearly confirms that the bearing alloy in the form of a composite can sustain heavier loads.

Keywords

• Bearing alloy, composite, particulate, reinforcement, hardness improvement

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