An Investigation on SiC and Al Surface Cladding of Ti-6Al-4V for Improved Wear Properties – The Binary Advantage | Chapter 6 | Current Approaches in Science and Technology Research Vol. 5

 Ti-6Al-4V has a high specific strength, toughness, and corrosion resistance, but it has a high friction coefficient, severe adhesive wear, and fretting wear sensitivity. One of the surface modification techniques used to improve on these flaws is laser surface cladding. Laser cladding makes use of the high power density of a focused laser source to heat and melt the surface of the substrate while injecting alloying elements into the melt pool. The surface cladding of the as-received Ti-6Al-4V alloy was done with different ratios of SiC and Al powders using a 4.4Kw continuous wave Nd-YAG laser processor. The SiC powder can act as reinforcing particles and aids in the construction process. The resulting surface metal matrix composite has improved surface wear properties, while aluminum improves wetting between the metal and the reinforcement SiC phase. However, the success of this is dependent on the careful optimization of the powder ratio, which dictates the resulting phases and microstructural evolutions. SEM (energy dispersive spectroscopy), optical microscopy, and x-ray diffraction analysis of the cladding revealed the formation of intermetallic phases such as AlSiTi2, Ti7Al5Si12, TiSi2, AlSi3Ti2, Al6Ti19, Ti2VAl, AlTi3, AlCTi2, Ti3SiC2 and Ti3SiC2. Ti5Si4, which should improve the surface's microhardness and tribological properties compared to the bulk as-received alloy. The best microhardness was 1169.95 Hv, compared to 323.67 Hv for the as-received, and mass loss under abrasive wear tests was only 40% of the as received. This improvement is also reflected in the morphology of the abraded surfaces. The binary combination of Al and SiC powders suffices for significantly improved Ti-6Al-4V surface properties in carefully optimized proportions and laser conditions. Ti5Si4, which should improve the surface's microhardness and tribological properties compared to the bulk as-received alloy. The best microhardness was 1169.95 Hv, compared to 323.67 Hv for the as-received, and mass loss under abrasive wear tests was only 40% of the as received. This improvement is also reflected in the morphology of the abraded surfaces. The binary combination of Al and SiC powders suffices for significantly improved Ti-6Al-4V surface properties in carefully optimized proportions and laser conditions.

Author (s) Details

U. O. Okoli
The Vaal University of Technology, Department of Metallurgical Engineering, Private Bag X021, Andries Potgieter Blvd, Vanderbijlpark, South Africa.

I. O. Otunniyi
The Vaal University of Technology, Department of Metallurgical Engineering, Private Bag X021, Andries Potgieter Blvd, Vanderbijlpark, South Africa.

I. D. Adebiyi
The Vaal University of Technology, Department of Metallurgical Engineering, Private Bag X021, Andries Potgieter Blvd, Vanderbijlpark, South Africa.

View Book :- https://stm.bookpi.org/CASTR-V5/article/view/1615