Laser metal deposition (LMD) is one of the most important laser additive manufacturing processes. It can be used to produce functional coatings, to repair damaged parts and to manufacture metal components. Ti6Al4V is one of the most commonly used titanium alloys, since it features a good balance of the mechanical properties of strength and ductility. The LMD of Ti6Al4V is attracting more and more attention from both science and engineering. The interest in processing Ti6Al4V with LMD in industry, especially in aerospace and medical branches, has been increasing in the last few years. In this paper, the state of the art for LMD of Ti6Al4V is reviewed. In the first part, the basics for Ti6Al4V, including, for example, the development history, the material properties, the applications, the crystal structure, the heat treatment and the mechanical properties, are introduced. In the second part, the main emphasis is on state of the art for LMD of Ti6Al4V. Initially, the process parameters of the current state of the art in the last years and their effects are summarized. After that, the typical microstructure after LMD is discussed. Then, the conducted heat treatment methods and the achievable mechanical properties are presented. In the end, some of the existing, current challenges are mentioned, and the possible research directions for the future are proposed.

Aluminum-magnesium-scandium-zirconium (AlMgScZr) alloys need to be rapidly cooled from the liquid state to obtain a high degree of solute supersaturation that helps to exploit the precipitation hardening potential of the material. While AlMgScZr alloys have been successfully used in laser powder bed fusion (LPBF) processes, there has been little research in the field of laser directed energy deposition (DED) of the material. The limited previous studies have shown that the performance of AlMgScZr parts fabricated with DED only reached about 60% of that of the parts fabricated with LPBF. In view of breaking through the limitation associated with the process conditions of conventional DED, this work demonstrates the DED of AlMgScZr alloys in high-speed process regimes and elucidates the mechanism of enhancing the hardness and tensile strength of AlMgScZr alloys by increasing the cooling rate by one to two orders of magnitudes, as well as reducing the track overlapping and the porosity of the specimens during the process. A maximum average hardness of nearly 150 HV0.1 and a max. tensile strength of 407 MPa are obtained by using an energy per unit length of 5400 J/m and a powder feed rate per unit length of 0.25 g/m.

The aim of the experiment was to investigate the interaction between Cu intake, inflammatory challenge and oxidative stress in broiler chickens. Furthermore, it was tested whether plasma ceruloplasmin (Cp) could be a sensible parameter for dietary Cu. One hundred forty-four day old chickens were raised on a basal control diet without added copper (Group Cu-6.5, basal Cu content 6.5 mg/kg diet) or a diet supplemented with Cu at 8 or 50 mg/kg (Groups Cu-14.5 and Cu-56.5, respectively) with four replicates of 12 animals for each treatment. Starting on day 21, chickens were injected intraperitoneally with lipopolysaccharides (LPS) once a day for 3 days. Before this challenge, Group Cu-14.5 had the lowest gain and the feed to gain ratio was the highest. After injection of LPS, however, chickens of Group Cu-14.5 had the best zoo-technical performance. For chickens of Group Cu-6.5, LPS injection resulted in elevated rectal temperature, and lower erythrocyte superoxide dismutase (CuZn-SOD) activity, compared with the other groups. LPS injection increased plasma uric acid in Group Cu-6.5 significantly, but was without influence in Group Cu-56.5. At all Cu-levels, LPS injection increased erythrocyte CuZn-SOD activity and decreased thiobarbituric acid reacting substances. No significant difference in plasma Cp was found in chickens fed different dietary Cu. LPS injection significantly increased plasma Cp in Group Cu-56.5. The results suggest that varying dietary Cu levels seem to modulate the parameters involved in immunological responses and oxidant stress and that plasma Cp is not a reliable parameter for dietaryCu.