Reutilization of nanosecond pulse laser energy and its performance in single particle triggered LIBS

A method that can reutilize the energy of a nanosecond pulse laser beam in LIBS was studied. When the pulse energy is not sufficient to generate the plasma, the overlapped point in this method can reach the threshold.

Evaluation of the Thermal Shock Fatigue Resistance of Cutting Tools Using a CO2 Pulse Laser Beam

It is well-known that a series of cracks sometimes gets initiated perpendicular to the cutting edges on the rake faces of brittle cutting tools made of materials such as cemented carbide, ceramics, and cermet under high-speed intermittent cutting. The tools used in intermittent cutting processes are exposed to elevated temperatures during cutting and then cool quickly during the noncutting time. Previous studies have suggested that such repeated thermal shocks generate thermal stress in the tool and that the thermal cracks are then propagated by thermal fatigue. Recently, high-speed machining techniques have attracted the attention of researchers. To apply new cutting tool materials to this machining process, it is important to evaluate their thermal shock fatigue resistances. During high-speed intermittent cutting, the frequency of thermal shocks becomes high and the action area of the thermal shocks is limited to the rake face of the tool. Therefore, conventional thermal shock resistance evaluation methods are unsuitable for this case. Consequently, the authors have developed a new experimental evaluation method using a CO2 laser beam. In this study, we irradiated cemented carbide and TiN cermet cutting tools with the CO2 pulse laser beam and gauged the effectiveness of the proposed thermal shock fatigue resistance evaluation method. The results show a correlation between the thermal shock due to the CO2 pulse laser beam and those due to the intermittent cutting experiments.

Particularity of the Forming Barcode Image on the Surface of Machine Parts when Marking with a Pulsed Laser

The article is devoted to some aspects of laser marking technology for machine parts. We consider the local impact zone effect of the pulse laser beam on the surface of metal materials. The results describing the influence of process parameters on the quality of the being marked images by pulsed laser are submitted. The examples of using barcode marking on several materials for machine parts in selected technological modes of installation are given.