the rapid melting of a semi- infinite body due to the absorption of a cw laser beam radiation has been studied. the enthalpy technique for the solution of phase change problems has been used in an explicit finite difference form to calculate the transient temperature distribution in the semi-infinite body and the growth rate of the melt pool. the technique has been modified so that it is not ne...

Despite considerable advances in of laser direct metal deposition (LDMD) process optimization, there is rather limited work reported on the effects of melt pool variables on the final deposit characteristics. This article considers the effects of process parameters and melt pool characteristics on the deposition of Inconel 718 powder on a Ti-6Al-4V thin wall. A 1.5kW diode laser and LDMD system...

The rapid melting of silicon film due to the absorption of a CW laser beam radiation is studied. The silicon film melting and recrystallization is mainly controlled by the temperature distribution in the semiconductor. The enthalpy technique for the solution of phase change problems is used in an explicit finite difference form to calculate the transient temperature distribution in the silicon ...

The effects of melt-pool geometrical parameters on crystal growth and microstructure development during laser surface melting of single-crystal alloys were studied by means of mathematical modeling and experiments. A mathematical model was developed for the three-dimensional (3-D) melt-pool geometry and single-crystalline melt-pool solidification in laser surface melting. The 3-D meltpool geome...

Melt pool temperature is of great importance to deposition quality in Laser Metal Deposition processes. To control the melt pool temperature, an empirical process model describing the relationship between the temperature and process parameters (i.e., laser power, powder flow rate, and traverse speed) is established and verified experimentally. A general tracking controller using the Internal Mo...

In this paper several approaches for the detection of the melt pool circle (i.e. its position and radius) in laser welding applications are described. Instead of indirectly examining the evolution of the melt pool via the radiation of plasma that is generated during the welding process, we use a direct view onto the melt pool that is possible in a narrow wavelength band with a coaxial aligned h...

This paper chronicles the development of a vision system for tracking melt pool morphology in the laser metal deposition process. This development is to augment an existing temperature feedback control system. Monitoring both the temperature and shape of the melt pool is necessary because of the effects of local geometry on the cooling rate at the melt pool. Temperature feedback alone cannot ac...

The mathematical model developed for single-crystalline solidification in laser surface melting (LSM) described in Part I [Acta Mater 2004;52:4833–4847] was used to compute the dendrite growth pattern and velocity distribution in the 3D melt pool for various substrate orientations. LSM experiments with single-crystal nickel-base superalloys were conducted for different orientations to verify th...

Melting of metallic plasma facing components such as tungsten (W) divertor, macroscopic melt motion, and melt splashing due to edge localized modes and plasma disruptions is a major concern in fusion devices such as ITER. The viscous stability analysis and computational modelling of coupled W-melt-plasma flows are performed using the developed volume-of-fluid magnetohydrodynamic code. The effec...