Bulletin of the Polytechnic Institute of Iași. Materials Science and Engineering Section

SYNTHETIC OVERVIEW OF STRUCTURAL ANALYSIS METHODS FOR METALLIC MATERIALS USING X-RAY DIFFRACTION

2026-02-25T08:40:12+02:00

Abstract. Identifying the structure of a material is not a trivial investigation process, especially considering the scale at which the investigation should be performed. An important method for such a study is the one known as "X-ray diffraction structure analysis". The initial purpose of X-ray diffraction was and remains to identify the structure of an unknown material. This type of analysis is much more favorable for the analysis of monocrystals of different substances, but for the analysis of polycrystalline materials the variant known as the "powder method" is used. Structural analysis by X-ray diffraction is based on X-ray diffraction by atomic planes inside the crystals. The result of the diffraction is the so-called diffraction pattern which is visualized in graphic form. This "diffraction pattern" has as its main characteristics the "peaks" or "diffraction maxima", which represent the angles (expressed as 2q, q being the angle expressed in degrees) at which the diffraction maxima are obtained.

A REVIEW OF THE CURRENT STATE OF RESEARCH ON WIRE DRAWING

2026-02-05T07:27:12+02:00

Abstract:

Wire drawing is one of the most popular technologies for obtaining finished products, which are then used in all industrial production sectors, from the household appliance, automotive, food, and construction industries to the aeronautical field. Parallel to the development of new wire drawing techniques, numerical and empirical approaches are being developed to improve existing methods and develop new wire drawing technologies. Many innovative numerical algorithms, experimental methods, and theoretical contributions have recently been proposed by researchers in the field. These methods are mainly focused on improving the deformability of materials, obtaining wires with increased mechanical strength, good surface quality, and minimal residual stresses, accelerating the production cycle, reducing the number of operations, and improving the environmental performance of production. The purpose of this study is to summarize recent development trends in both the numerical and experimental fields of conventional wire drawing methods, as well as in the field of new severe plastic deformation (SPD) wire drawing methods. Particular attention was paid to the period 2015-2025 regarding the progress in the development of methods for drawing difficult-to-process materials for automotive and aircraft applications, tribological aspects that have become a subject of great attention, and the assessment of the ecological impact of wire drawing processes.

Key words: drawing, wires, review, severe plastic deformation, properties, structure.

A ASSESSMENT OF CORROSION RESISTANCE IN Ni-Cr-BASED COATINGS FABRICATED VIA COLD SPRAY TECHNIQUE

2026-05-19T09:15:41+03:00

The Cold Spray deposition method differs from traditional thermal spray techniques in that it operates at lower temperatures, allowing particle deposition without melting the material. This preserves the intrinsic properties of the sprayed particles and minimizes thermal degradation, whereas thermal spray methods involve melting the particles, which can lead to oxidation, residual stresses, and changes in material structure upon solidification. In our study, we examined the corrosion resistance of 4340 steel coated with a Ni/chromium carbide (Ni/CrC) particle blend. Electro-corrosion testing confirmed that the deposited layer has a near-intact condition, with only minimal compound traces found in the electrolyte solution, indicating substantially lower oxidation in the coating than in the base material.

Enhancing the Mechanical Properties of Biodegradable Zinc Alloys through Severe Plastic Deformation Techniques

2025-12-08T15:09:06+02:00

Zinc-magnesium (Zn-Mg) alloys have emerged as promising candidates for biodegradable implants due to their excellent biocompatibility and controlled degradation rates. However, their limited mechanical properties often hinder their practical applications. In this study, hydrostatic extrusion (HE) and equal channel angular pressing (ECAP) were employed to enhance the microstructure and mechanical properties of a Zn-1%Mg alloy. The effects of these severe plastic deformation techniques on grain size, dislocation density, and tensile properties were investigated. The results demonstrated that both HE and ECAP significantly refined the microstructure, leading to substantial increases in strength and ductility. The enhanced mechanical properties were attributed to the synergistic effects of grain boundary strengthening and dislocation strengthening mechanisms. Furthermore, the study suggests that HE-processed and ECAP-processed Zn-Mg alloys have the potential to be used in various biomedical applications, such as biodegradable stents and orthopedic implants.

CREATING ADDICTIVE BEHAVIOR TO ENHANCE SUSTAINABLE FASHION CONSUMPTION: A BEHAVIORAL PSYCHOLOGY APPROACH

2026-02-19T15:29:42+02:00

The fashion industry faces a critical sustainability challenge, with fast fashion contributing significantly to environmental degradation and social inequity. This research explores how behavioral psychology principles, habit formation mechanisms, and gamification strategies can be leveraged to create engaging, potentially addictive behaviors that promote sustainable fashion consumption. Drawing on recent research, we examine the psychological drivers of consumer behavior, the attitude-behavior gap in sustainable consumption, and innovative interventions including nudging, choice architecture, and eco-gamification platforms. Key findings indicate that gamification elements such as progress tracking, rewards systems, and social competition can effectively engage consumers in sustainable practices. However, the application of addictive design patterns raises important ethical considerations regarding consumer autonomy and transparency. This article provides a comprehensive framework for designing behavioral interventions that balance effectiveness with ethical responsibility, offering practical applications for fashion brands, policymakers, and digital platform designers seeking to promote circular economy practices in the textile and clothing sector.