Ultra-short pulsed laser ablation may be used for high-precision machining with very low thermal influence on the processed materials. Due to this reason, lasers are increasingly used for processing of advanced materials, such as titanium alloys, nickel-based alloys or steel, every year. In this study, four advanced technical materials were analysed and compared under femtosecond laser irradiation with three different wavelengths. The main laser-material interaction parameters were identified, namely the ablation threshold and removal efficiency parameters. Higher removal rates were found for Ti6Al4V alloy with all three harmonic wavelengths. To increase process productivity, a method of increasing the repetition rate and scanning speed was presented. With the maximum repetition rate, the productivity increased five-fold with a similar removed depth and surface quality. Finally, the suitability of the identified parameters with regard to quality and productivity was demonstrated for fabrication of two complex structures – honeycomb and dot – which has the potential to improve friction properties of advanced materials.

The paper describes a computationally convenient analytical formulation of the stability of the cutting process with respect to self-excited vibrations in the case of five-axis milling based on the commonly used zero-order approximation. In the case of five-axis milling with general milling cutters, it is difficult to calculate stable machining process conditions for two main reasons. The first reason is the difficulty of calculating the mean value of the cutting force Jacobian with respect to the regenerative displacement (closely related to a milling directional matrix) for a generally inclined tool, and the second reason is the nonlinearity of this Jacobian with respect to the process parameters, which means that the problem cannot be reduced to a linear eigenvalue problem as is usual for linear cases (e.g. cylindrical milling with respect to the axial depth of cut). In the first part, this paper presents a modification of the calculation of the machining stability limits for a nonlinearly dependent cutting force Jaco-