Due to the expansion of the use of powder bed fusion metal additive technologies in the medical field, especially for the realization of dental prostheses, in this paper, the authors propose a comparative experimental study of the mechanical characteristics and the state of their microscale surfaces. The comparison was made from material considerations starting from two dental alloys commonly used to realize dental prostheses: Ni-Cr and Co-Cr, but also technologies for obtaining selective laser melting (SLM) and conventional casting. In addition, to compare the performances with the classical casting technology, for the dental prostheses obtained through SLM, the post-processing stage in which they are in a preliminary finishing and polished state was considered. Therefore, for the determination of important mechanical characteristics and the comparative study of dental prostheses, the indentation test was used, after which the hardness, penetration depths (maximum, permanent, and contact depth), contact stiffness, and contact surface were established, and for the determination of the microtopography of the surfaces, atomic force microscopy (AFM) was used, obtaining the local areal roughness parameters at the miniaturized scale—surface average roughness, root-mean-square roughness (RMS), and peak-to-peak values. Following the research carried out, several interesting conclusions were drawn, and the superiority of the SLM technology over the classic casting method for the production of dental prostheses in terms of some mechanical properties was highlighted. At the same time, the degree of finishing of dental prostheses made by SLM has a significant impact on the mechanical characteristics and especially the local roughness parameters on a miniaturized scale, and if we consider the same degree of finishing, no major differences are observed in the roughness parameters of the surfaces of the prostheses produced by different technologies.

Many projects and researches in the field of remanufacturing of specialized lathes are presented in the specialized literature. In the process of design for remanufacturing, a great number of solutions contain different aspects and data important to consider. The paper presents important stages of theoretical and applied research regarding the modernization of a conventional lathe with two working units by adaptation of four driving chains for CNC advance/positioning movements and improvements of translation couplings, adaptation of CNC equipment for driving and measuring simultaneous both wheels mounted on axle. The reducing of geometrical errors of the running profile is very important in reshaping the worn wheelsets. The lathe remanufacturing process involves the restoration of functional requirements and measurement of the geometric precision. The CNC capabilities of the remanufactured lathe require a database of parametric representation of profiles and rolling surfaces using CAD techniques according to international standards.

Harmonic analysis is a mathematical method that performs the determination (approximation) of continuous functions by the sum of ideal sinusoids. By selecting these sinusoids in a judicious way, in defining the methods of smart measurement of a part, it is possible to separate the geometrical elements of a part into geometric elements of the shape (circularity, eccentricity, etc.) of the geometric elements corresponding to the state surfaces. This article, using the research carried out under the doctoral thesis “COMPLEX STUDIES, RESEARCH AND EXPERIMENTATION OF PRECISION MECHANICAL GEARING TRANSMISSIONS USING HIGH PRECISION HARMONICS METHODS ”, aims to perform an original work and thus to present and analyze the main methods of processing the data gathered in the process measurement of the parts made and used in mechatronic equipment by resorting to harmonic analysis.

Before processing, mechanical vibrations need measurement and some raw processing steps are necessary as filtering, digitization and transmission. Examples of specialized equipment and applications are presented and discussed, mainly from technological point of view.