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A new classification of different laser beam induced surface engineering technologies is offered in this paper. An in situ laser melt injection technology is applied in this paper to modify the surface of an inexpensive carbon steel substrate. Relatively large WCzTi particles were blown into a laser melt steel pool, and the desired (Ti,W)C carbide particles were precipitated upon cooling and solidification. Although these primary (Ti,W)C carbide particles were micrometre sized, additional nanosized (Fe,W) 6 C particles were found to precipitate during the subsequent heat treatment from an oversaturated steel matrix. Thus, a steel matrix surface nanocomposite was produced by the combination of in situ laser melt injection technology and subsequent heat treatment.

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Experiments are run to show that different machining conditions applied to ultra-fine grained pure titanium lead to different levels of grain coarsening and softening near the machined surface. Under “hard” machining conditions the upper 40 microns of the machined surface are altered with a decreased microhardness. The experimental results are reasonably reproduced by model calculations. Expanding the parameter field of the model calculations, the surface coarsening diagram and the surface softening diagram due to machining are presented, showing the region of technological parameters, under which neither grain coarsening nor softening takes place along the machined surface

In the present study the analysis of 5 different mechanisms of porosity formation during laser melt injection (LMI) technology were performed. Experiments were supported by thermodynamic and fluid-flow analysis. Special attention should be paid to i. clean the surface of the substrate, ii. use inert shielding gas, iii. use proper particle size and gas velocity, iv. use proper laser power and laser beam velocity to control bath temperature and v. deoxidize the surface of the added particles.