Hybrid Layered Manufacturing of Turbine Blades

Hybrid Layered Manufacturing (HLM) is a Rapid Manufacturing (RM) process of metallic objects, which combines the best features of additive and subtractive manufacturing techniques. Similar to other RM processes, HLM also proceeds in the layer by layer manner. 3D CAD model is sliced into thin 2D layers and the tool pathsaregenerated for each layer. The deposition of metal according to the generated tool path can be done using a Metal Inert gas (MIG), Tungsten Inert gas (TIG) and LASER cladding process. The different characteristics of these three cladding methods such as speed, precision and cost, make them useful for different applications. After the deposition of near net shape, the machining process is used to provide the final dimensional accuracy. So far Aluminium, Mild steel and Tool steels have been used for HLM process andother super alloys such as Titanium and Inconelwill be explored soon. The process parameters such as cladding current, stepover and torch speed have been optimized to achieve the desired thickness of the layers and spatter free cladding. Several build strategies have been developed and incorporated through an in-house build software. One of the strategy called integrated substrate method, found its application in the manufacturing of turbine blades, ribs, and spar/bulkhead structures of aircrafts. In this work this strategy has been explained and its capability has been proved through the manufacturing of turbine blade as a case study. (C) 2017 Elsevier Ltd. All rights reserved.