Strategical parametric investigation on manufacturing of Al–Mg–Zn–Cu alloy surface composites using FSP

ABSTRACT

Friction stir processing (FSP) is a unique approach being presently researched for composite fabrication. In the present investigation, Al-B₄C surface composite was fabricated through FSP by incorporating B₄C powder particles into Al–Mg–Zn–Cu alloy (AA 7075) matrix. The influence of varying powder particle reinforcement strategies on the microstructure, powder distribution, microhardness, and wear resistance of the surface composite is reported. In addition, AA 6061/B₄C composites were prepared using the same parameter set and the powder distribution in the composite was compared to that in the AA 7075/B₄C composite. More homogeneous dispersion of B₄C powder was observed in AA 6061 as compared to AA 7075 substrate. Among the prepared AA 7075/B₄C composites, the best B₄C powder distribution was detected in samples processed using fine powder and incorporating the change in stirring direction between passes. The hardness and wear resistance of the prepared composites were almost doubled attributing to several strengthening mechanisms and B₄C powder distribution in the AA 7075 matrix.

KEYWORDS:

• Aluminum
• boron
• carbide
• composites
• microhardness
• microstructure
• processing
• wear

Acknowledgments

It is our honor to thank the Indian Space Research Organization, Government of India (in collaboration with Space Application Centre, Ahmedabad), for providing financial assistance for a project under RESPOND program (Project number—ISRO/RES/4/567/09-10). Under this project, vertical milling machine and consumables had been funded and used for experiments conducted. We are also thankful to Dr. Nirav Jamnapara and Mr. Arun Zhala from Facilitation Centre for Industrial Plasma Technologies (FCIPT) for extending their kind support for XRD analysis.

Notes

¹The Cu peak observed in EDAX analysis might be due to the TEM sample holder (single tilt holder was used). The phase, therefore, may be MgZn₂ only.