This research work was focused on the laser peening surface process in a metallic Ti-6Al-4V biomaterial. The Ti-6Al- 4V samples were surface treated at different laser conditions varying parameters such as pulse density and wave length. Laser peening induced effects were evaluated by synchrotron radiation X-ray diffraction (SR-XRD) to determine the residual stress state; scanning electron microscopy (SEM) to assess microstructural changes and thermoelectric testing (TEP) to sense the subtle material variations such as local texture, increased dislocation density, hardening and residual stresses degree. The TEP measurements demonstrate that the non-contact technique is very sensitive to the compressive residual stresses with increasing the severity of the laser treatment parameters, while the TEP contact results are closely related to grain size, cracks, anisotropy, and work hardening.
Laser cladding processing has been used in different industries to improve the surface properties or to reconstruct damaged pieces. In order to cover areas considerably larger than the diameter of the laser beam, successive partially overlapping tracks are deposited. With no control over the process variables this conduces to an increase of the temperature, which could decrease mechanical properties of the laser cladded material. Commonly, the process is monitored and controlled by a PC using cameras, but this control suffers from a lack of speed caused by the image processing step. The aim of this work is to design and develop a FPGA-based laser cladding control system. This system is intended to modify the laser beam power according to the melt pool width, which is measured using a CMOS camera. All the control and monitoring tasks are carried out by a FPGA, taking advantage of its abundance of resources and speed of operation. The robustness of the image processing algorithm is assessed, as well as the control system performance. Laser power is decreased as substrate temperature increases, thus maintaining a constant clad width. This FPGA-based control system is integrated in an adaptive laser cladding system, which also includes an adaptive optical system that will control the laser focus distance on the fly. The whole system will constitute an efficient instrument for part repair with complex geometries and coating selective surfaces. This will be a significant step forward into the total industrial implementation of an automated industrial laser cladding process.