Evaluating the Methods Used for the Regeneration Process of Copper-Zinc Solutions

The purpose of this study was to investigate the physicochemical particularities of the regeneration processes that occur in spent sulphate copper-zinc solutions using the reagent methods of crystallization, cementation, and sedimentation. A comparative analysis of the results of the studies of regeneration processes has shown that the content of the extraction of Cu2+ and Zn2+ ions by the crystallization method makes up to 97.2% and 49.7%, respectively; by the contact displacement method to 99.9% and 95.4%, respectively; and by the deposition method it makes up to 99.9% and 99.9%, respectively. The presented study can be used for improvements in the electroplating productivity.

Development of a Compound Speckle Interferometer for Precision Three-Degree-of-Freedom Displacement Measurement

In this study, a compound speckle interferometer for measuring three-degree-of-freedom (3-DOF) displacement is proposed. The system, which combines heterodyne interferometry, speckle interferometry and beam splitting techniques, can perform precision 3-DOF displacement measurements, while still having the advantages of high resolution and a relatively simple configuration. The incorporation of speckle interferometry allows for non-contact displacement measurements by detecting the phase of the speckle interference pattern formed from the convergence of laser beams on the measured rough surface. Experiments were conducted to verify the measurement capabilities of the system, and the results show that the proposed system has excellent measurement capabilities suitable for future real-world applications.

Viscoelastic Resistance of the Surface Layer of Steel Products to Shock Attack of a Spherical Pellet

The results of experimental studies of a separate contact dynamic interaction of a spherical non-deformable pellet with a plastic flat metal surface at different angles of attack (20° ≤ α ≤ 90°) at high speeds (v ≈ 100m/s) are presented. A method is described for determining the nature of the viscoelastic resistance of a surface layer attacked by a pellet during contact displacement along the normal to the surface and rigid plastic resistance during tangential displacement, which can be used to establish the processing regimes of products by a mass flow of abrasive particles, in particular, shot-blasting cleaning. The results of comparing the obtained and known theoretical data with each other and with experimental studies are presented.

Contact simulation analysis of double cylindrical asperities using the finite element method

To analyze the microcontact characteristics of the rough joint surface obtained by grinding more accurately, a frictionless contact model of double cylindrical asperities was established. The contact characteristics of double cylindrical asperities with different peak distance and different heights were analyzed using the finite element method. The relationship between contact load, contact pressure, contact area, and contact displacement were studied. And the effect of double asperities on the stress state of the cylindrical asperity contact zone was revealed. The results show that, in the elastic contact stage, the contact load, contact stress, contact pressure, and contact area decreased with an increase in the peak distance, and the corresponding values are smaller than that of single peak asperity contact. In the elastoplastic stage, because of the interaction of the double asperities, the change of the contact pressure with the contact displacement on the double asperities contact is larger than the corresponding value of the single peak asperity under the same conditions. The research can be applied into the model of anisotropic interface and provide theoretical foundations for the study on contact characteristics of grinding interface.

Design of a Tribotester Based on Non-Contact Displacement Measurements

A tribotester with an integrated load sensor based on a strain gauge is typically used to measure the friction coefficient generated by the contact-related sliding motion of two objects. Since the friction coefficient is obtained by dividing the measured friction force by the applied normal force, the normal and friction forces must be measured for accurate analysis. In this study, a tribotester was used to measure the displacement of a cantilever tip using the fiberoptic sensor in a non-contact method. The friction coefficient measurement using the fiberoptic sensor was proven to be valid by calibrating the tip displacement due to normal/friction forces after designing a basic structural cantilever tip based on experiments and simulation analyses. The results obtained by using the fiberoptic sensor-cantilever tip-based tribotester were compared with those obtained using commercial and/or custom-built tribotesters under the same conditions. By designing various shapes of cantilever tips and using simulation analysis, the calibrations of the normal/friction forces and tip displacement could be verified and the coupling effect was evaluated. The performance and reliability of the fiberoptic sensor-cantilever tip-based tribotester, which can be used to determine the normal/friction forces by non-contact displacement measurements without a strain gauge, were verified.