The prospects for direct laser deposition in the manufacture of 316L austenitic stainless steel parts are assessed. The influence of the power of the laser beam and the state of the initial material on the structure and properties of the product is considered.

The mechanical and service properties of Ti-6Al-4V alloy parts produced by direct laser deposition (DLD) depend on the thermal cycle parameters. The temperature field during deposition is significantly affected not only by the parameters of the process, but also by the interpass dwell time and length of the deposited layers. The aim of the article is to establish the relationship between mechanical properties of deposited Ti-6Al-4V samples and DLD thermal cycle parameters. Numerical simulation was used in order to establish relationship between temperature field parameter and the process parameters. The nonlinear three-dimensional heat conduction problem was solved by the finite element method. It is shown that an increase in the dwell time between passes from 5 to 10 seconds leads to a significant decrease in the inter-pass temperature and an increase in the cooling rate. This leads to the metastable structure formation of the deposited layers of Ti-6Al-4V that consists mainly of a nonequilibrium a’-phase which hardness is higher than 390 HV. Without dwell time an equilibrium a + (3 structure with hardness of 360 HV and higher elongation is formed.

This work is devoted to the microstructure, tensile deformation and microhardness behaviour of Ti-6Al-4V alloy fabricated using direct laser deposition additive manufacturing with using different oxygen concentration in protected chamber. The results show that the microstructure consists of coarse columnar prior-β grains and α-laths, with decreasing of oxygen concentration a β-phase amount is reduce. Ti-6Al-4V alloy has a basket-weave microstructure in the atmosphere with concentration of oxygen up to 0,25%, also it has higher concentration martensitic structure. Using local protection it is impossible to achieve the necessary mechanical characteristics. The required properties for Ti-6Al-4V are achieved with an oxygen content in the chamber in the range of [0,02-0.25]%, further reduction of the content is meaningless, since the mechanical properties vary slightly and higher 0,5 mechanical properties of samples is decreased.

In this study, a composite with alternate layers of 5056 and 1580 alloys was manufactured with wire arc additive manufacturing technology. It is shown that increased strength characteristics of composite material can be obtained with deformation treatment using a high-pressure torsion (HPT) technique. The microstructure and mechanical properties of the HPT-processed material in different structural states were investigated. The HPT-processed material exhibits a high value of ultimate tensile strength (~770 MPa) but low ductility. Short-term annealing at 250 °C and additional deformation with HPT to 0.25 of revolution at room temperature resulted in a slight decrease in the material’s strength to ~700 MPa but provided ductility of ∼9%. Physical mechanisms to improve plasticity in correlation with microstructure evolution are discussed.

Additive technologies as an alternative to traditional methods arouse great interest in many industrial sectors. In recent years, many theoretical and experimental articles devoted to additive technologies and their applications have been published. In spite of it, now the area of outstanding issues is still remaining. The paper presents results of theoretical and experimental researches devoted to the stability of products formation from different metallic alloys with complex geometry form, which were manufactured using high-speed direct laser deposition technology. The prospect of application of the method for the manufacturing of various materials details and products for various areas of engineering has been shown.

In this study composite with alternate layers of 5056 and 1580 alloys was manufactured by wire arc additive manufacturing technology. It is shown that increased strength characteristics of composite material can be obtained due to deformation treatment by high-pressure torsion (HPT) technique. The microstructure and mechanical properties of the HPT-processed material in different structural states were investigated. The HPT-processed material exhibits high value of ultimate tensile strength (~ 770 MPa) but low ductility. Short-term annealing at 250 oС and additional deformation by HPT to 0.25 of revolution at room temperature resulted in a slight decrease in material’s strength to ~ 700 MPa but provided ductility ∼ 9%. Physical mechanisms to improve plasticity in correlation with microstructure evolution is discussed.