Laser assisted rapid manufacturing technique for the manufacturing of functionally graded materials

Abstract

Functionally Graded Material (FGM) is a material with engineered gradients of composition, structure and/or specific properties aiming to become superior over homogeneous material composed of same or similar constituents. In the recent years, research has been undertaken on manufacturing of functionally graded materials (FGM) using numerous techniques like powder metallurgy, melt processes, centrifugal casting, electrophoretic deposition, spark plasma sintering, physical vapor deposition, chemical vapor deposition etc. Most of these techniques may be well suited for a specific application yet they suffer from one or more limitations like lower graded thickness, low deposition rate, complexity in process requirement, or high processing cost. To circumvent these limitations innovative technique called laser assisted manufacturing technique is applied for manufacturing functionally graded materials. Three methods that employ Laser for synthesis of FGM is elaborated in this work (i) 3-D Laser Cladding, (ii) LENS and (iii) Selective laser sintering. Laser Cladding is used for obtaining coatings of FGM by direct powder injection into the laser beam. 3-D Laser-engineered net shaping (LENS) is used to fabricate FGM directly from CAD solid models and thus further reduce the lead times for metal art fabrication. Selective laser sintering (SLS) is a layered manufacturing based freeform fabrication approach for constructing three dimensional structures in functionally graded composites. All these methods are used to manufacture FGMs in a short interval of time and the process can be controlled digitally, thus all these methods come in the heading of rapid manufacturing (RM). These methods have a huge industrial potential and can be commercialized for manufacturing bulk FGM.