FAKE DRIVERS AND CERTIFICATES FOR REGISTRATION OF VEHICLES MANUFACTURED ON POLYMER III GENERATION, EXAMPLE EXAMPLES

Thus, the described documents on a plastic basis have a number of significant drawbacks. These factors contribute to the legalization of stolen and non-cleared vehicles, which in turn leads to costly losses and shortfalls in the budget of significant funds, as well as the use of fake driver’s licenses. To correct this situation, it is necessary to strengthen the protection of this type of documents by applying additional protection methods, for example: inscriptions or images that will be damaged when deleting personal data, leaving traces of erasing, applying personal data by laser engraving. Applying the document number after personalization by laser perforation or volumetric laser engraving, it is also necessary to establish effective control over consumables. These issues are most effectively resolved when implementing centralized personalization of this type of documents.

Experimental Investigation on Hard Rock Breaking with Fiber Laser: Surface Failure Characteristics and Perforating Mechanism

The rock-breaking characteristics and the influence factors of laser perforation are investigated in this study. A series of fiber laser perforation experiments on basalt, sandstone, and granite were conducted. Experimental measurements of rock failure morphologies and composition tests showed that the main surface features are thermal cracks and glazed layer formed by the melting and condensing of rock in laser perforation. It is also found that higher quartz content could help reduce the glazed degree of rock. Comprehensive results showed that the laser rock perforation is mainly formed by thermal fractures, the decline of molten pool, and the evaporating and splashing of the special melted rock components. The depth of rock perforation and SE usually increase with the laser irradiation time, while the ROP gradually decreases. With the increase of laser power, the perforation depth and ROP gradually increase, while the SE initially decreases and then increases indicating that there is an optimal power that maximizes perforation efficiency. It is believed that the strength of rock is the main factor affecting laser perforation efficiency, and the lower rock strength resulted in deeper perforation depth, higher ROP, and lower SE.

Features of laser drilling of porous aluminosilicate ceramics

Studies have shown that local laser heating/“drilling” of composite large-porous ceramics consisting of aluminosilicates and glass phase is based on melting and ablation processes that lead to the formation of holes in a porous specimen. The interaction of the components of the composite in the high-temperature heating zone is accompanied by the formation of glass-phase melt of new composition. The advance of the melt deep into the sample along channel-like pores of the main ceramic material depends on the viscosity of the melt (i.e., the irradiation mode) and the cooling rate of the melt (i.e., the thermo-physical properties of the ceramics and glass phase). The development of gas-dynamic impact in the laser heating zone leads not only to the ejection of a part of the melt from the channel, but also to the compaction of the ceramics adjacent to the walls of the vitrified channel. These effects depend heavily on the ceramic-to-glass phase ratio and the porosity of the initial ceramic. It has been established that “laser perforation” of highly porous aluminosilicate ceramics leads to the hardening of the coarse-porous ceramics due to the formation of holes with strong walls, consisting of layers of the glass phase and compacted ceramics in the sample.

Thermal/Mechanical Interaction in Laser Perforation Process: Numerical-Model Buildup and Parametric Study

Summary In this paper, a generic thermal/mechanical interaction model was developed to predict the penetration rate and mechanical damage around perforation tunnels that resulted from the laser perforation of rock samples. The perforating process is driven by heat emitted by a laser beam directed at the surface of a sample. The temperature propagation, thermal expansion, and thermal/mechanical interaction were modeled by coupling heat conduction in solid media with the elastic/plastic constitutive mechanical response of rocks. The phase changes that occur during the melting and evaporating process were accounted for in the latent heat of fusion and of vaporization. The heating boundary was updated dynamically along with the evolution of perforation channels. The model was used to parametrically investigate the effects of material properties, stress ratio, and laser–beam characteristics on the penetration rate and mechanical damage.