Search Results (4)

This paper presents a comparison between four TRIP steels, which belong to two groups with different chemical compositions. The first group is that of steels with a relatively low contents of Mn (1.5–2%), high Al (1–2%) and about 0.2% C, and the second includes steels with lower percentages of C (0.1%) and Al (max. 0.6%), but with high percentages of Mn (over 5%). The steels were heat treated by incomplete austenitization, isothermally cooled in salt baths at 400 °C, followed by air cooling. The heat-treated samples were subjected to the impact bending test. A comparative study was performed from the point of view of the intensity of the TRIP effect, the development of the retained austenite-to-martensite transformation under shock (studied by SEM), X-ray analysis and hardness measurements. It was found that appropriate and similar behaviors in terms of mechanical shock were shown by two steels belonging to different groups, with similar amounts of the retained austenite being turned into martensite fractions. The steel with the highest Mn percentage was distinguished by having the highest hardness (362 HV) and the highest retained austenite (obtained after heat treatment) and martensite fractions (caused by the TRIP effect) (10.63% and 2.17%, respectively). Full article

The scholarly literature records information related to the performance increase of the cutting tools covered by the superficial layers formed “in situ” when applying thermochemical processing. In this context, information is frequently reported on the carbamide role in processes aiming carbon and nitrogen surface saturation. Sulfur, together with these elements adsorbed and diffused in the cutting tools superficial layers, undoubtedly ensures an increase of their operating sustainability. The present paper discusses the process of sulfonitrocarburizing in pulverulent solid media of high-speed tools steel (AISI T1, HS18-0-1) and its consequences. The peculiarity of the considered process is that the source of nitrogen and carbon is mainly carbamide (CON₂H₄), which is found in solid powdery mixtures together with components that do not lead to cyan complex formation (non-toxic media), and the sulfur source is native sulfur. The kinetics of the sulfonitrocarburizing process, depending on the carbamide proportion in the powdered solid mixture and the processing temperature, was studied. The consequences of the achieved sulfonitrocarburized layers on the cutting tools’ performance are expressed by the maximum permissible cutting speed and the maximum cut length. An interesting aspect is highlighted, namely the possibility of using chemically active mixtures. Their components, by initiation of the metallothermic reduction reaction, become able to provide both elements of interest and the amount of heat needed for the ultrafast saturation of the targeted metal surfaces. Full article

Biosimilar medicines expand the biotherapeutic market and improve patient access. This work looked into the landscape of the European and US biosimilar products, their regulatory authorization, market availability, and clinical evaluation undergone prior to the regulatory approval. European Medicines Agency (EMEA, currently EMA) and Food and Drug Administration (FDA) repositories were searched to identify all biosimilar medicines approved before December 2019. Adalimumab biosimilars, and particularly their clinical evaluations, were used as a case study. In the past 13 years, the EMA has received 65 marketing authorization applications for biosimilar medicines with 55 approved biosimilars available in the EU market. Since the first biosimilar approval in 2015, the FDA has granted 26 approvals for biosimilars with only 11 being currently on the US market. Five adalimumab biosimilars have been approved in the EU and commercialized as eight different medicines through duplicate marketing authorizations. Whilst three of these are FDA-approved, the first adalimumab biosimilar will not be marketed in the US until 2023 due to Humira’s exclusivity period. The EU biosimilar market has developed faster than its US counterpart, as the latter is probably challenged by a series of patents and exclusivity periods protecting the bio-originator medicines, an issue addressed by the US’s latest ‘Biosimilar Action Plan’. Full article

The need to increase the reliability of the metal parts and the assessment of the cost-quality parameters of a matrix require big manufacturers to find new technological solutions focused on the following aspects: thin layer deposits, metallic coatings, use of bimetals, and multilayer materials. The coating of the copper-based quaternary alloys with carbon graphite impregnated polyester aims to improve the performance of the metal parts used in the aeronautics, automotive, and railway industries. The goal is to achieve the following objectives: to reduce the rate of premature failure, to reduce the maintenance and service costs, and to increase the service life (the competitiveness of the manufacturing companies is positively influenced by the latter). This paper studies the operating behavior of some copper-based quaternary alloys coated with carbon graphite-impregnated polyester. The influence of the carbon graphite coating is studied in terms of operating behavior, especially aiming to assess the intensity of the wear and the intensity of the accumulated wear. On the whole, proper wear behavior entails the possibility of obtaining an increase in the service life. Full article