Laser metal deposition of steel components using machining waste as build material
Gas atomised metal powders are generally used in laser cladding. However, costly new powders prompt the use of machining swarf as an alternative build material. This paper reports on this investigation and establishes its feasibility.
Microstructure and properties of thin wall by laser cladding forming
Laser cladding forming is a layer additive manufacturing technique and can be used to fabricate three-dimensional fully dense metal components directly from the CAD model with neither mould nor tool. It has shown extensive application on many fields and has been intensively developed. An investigation of laser cladding forming for Ni-based tungsten carbides (WC) thin wall is presented in this paper. The phase constitution, microstructure and microhardness were investigated by X-ray diffractometer, energy dispersion spectroscopy, scanning electron microscope and Vickers hardness tester. The characteristics of the thin wall were studied also. The results showed that the undissolved tungsten carbides uniformly dispersed in the matrix of the Ni-based alloy. A preferable bonding mode between WC particle and nickel-based alloy matrix was observed in the thin wall. The Vickers hardness across the longitudinal section of the sample in the height-direction shows a periodical fluctuation due to the secondary heating.
Laser welding of Waspaloy® sheets for aero-engines
Abstract Laser welding techniques have been characterised for various materials, using different laser sources. However, such research has not been performed on superalloys used in aero-engine fabrication and maintenance. In this paper, the laser weldability of a nickel-base alloy. Waspaloy, is investigated using CO 2 and Nd:YAG lasers. The results indicate that the microfissures that occur at the grain boundary in the heat-affected zone linked with the fusion zone are reduced by decreasing the welding speed and the material thickness. Metallurgical analysis reveals fine Ni 3 (AlTi) precipitation and MC carbides in the fusion zone. A casing for aero-engines made of 2 mm thick Waspaloy sheets has been assembled using laser cutting and welding technology.