A5078984744- Additive Manufacturing Materials and Processes
- High Entropy Alloys Studies
- Welding Techniques and Residual Stresses
- Additive Manufacturing and 3D Printing Technologies
- Bone Tissue Engineering Materials
- Laser Material Processing Techniques
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Surface Treatment and Coatings
- 3D Printing in Biomedical Research
- Dental Implant Techniques and Outcomes
- Titanium Alloys Microstructure and Properties
- Thermography and Photoacoustic Techniques
- Brake Systems and Friction Analysis
- Nonlinear Optical Materials Studies
- Surface Treatment and Residual Stress
- Dental materials and restorations
- Advanced Combustion Engine Technologies
- Aluminum Alloys Composites Properties
- Fusion materials and technologies
- Spacecraft and Cryogenic Technologies
- Rocket and propulsion systems research
National Institute for Laser Plasma and Radiation Physics
2017-2024
Universitatea Națională de Știință și Tehnologie Politehnica București
2019-2021
Additive manufacturing (AM) processes can produce three-dimensional (3D) near-net-shape parts based on computer-aided design (CAD) models. Compared to traditional processes, AM generate with intricate geometries, operational flexibility and reduced time, thus saving time money. On the other hand, face complex issues, including poor surface finish, unwanted microstructure phases, defects, wear tracks, corrosion resistance fatigue life. These problems prevent from real-time applications....
A major limitation of existing 3D implantable structures for bone tissue engineering is that most the cells rapidly attach on outer edges structure, restricting penetration into inner parts and causing formation a necrotic core. Furthermore, these generally possess random spatial arrangement do not preserve isotropy whole volume. Here, we report fabrication testing an innovative hierarchical, honeycomb-like structure (HS), with reproducible isotropic arhitecture, allows in 'volume' migration...
In this study, crack-free TiC/Ti composites with TiC content ranging from 0 to 15 wt.% were successfully fabricated using Direct Energy Deposition a dual-feeder system that concomitantly delivered different amounts of both constituents into high-power laser beam. The samples investigated evaluate the morphologies and distribution behavior TiC. microhardness values obtained under optimal processing conditions increased 192 ± 5.3 HV
Powder flow and temperature distribution are recognized as essential factors in the laser melting deposition (LMD) process, which affect not only layer formation but also its characteristics. In this study, two mathematical models were developed. Initially, three-jet powder Gaussian shape was simulated for LMD process. Next, coaxially added along with moving beam to investigate effect of on at substrate. The particles’ inflight within melt-pool heating times controlled avoid vapors or plasma...
Laser melting deposition is a 3D printing method usually studied for the manufacturing of machine parts in industry. However, medical sector, although feasible, applications and actual products taking advantage this technique are only scarcely reported. Therefore, study, Ti6Al4V orthopedic implants form plates were printed by laser deposition. Tuning power, scanning speed powder feed rate was conducted, order to obtain continuous after single pass diminish unwanted blown powder, stuck...
Many of the significant mechanical properties stainless steel, including ultimate tensile strength, yield strength and hardness, ductile–brittle transition temperature, susceptibility to environmental embrittlement, can be improved by grain size refinement. Hall-Petch relation identifies that improvement quantified in a constitutive relation. In this study, new mathematical model calculate number grains their average inside single printed layer via laser melting deposition (LMD) process is...
Laser Melting Deposition (LMD) is a metal printing technique that allows for the manufacturing of large objects by Directed Energy Deposition. Due to its versatility in variation parameters, possibility use two or more materials, create alloys situ produce multi-layer structures, LMD still being scientifically researched and far from industrial maturity. The structural testing obtained samples can be time consuming solutions decrease analysis are constantly proposed scientific literature. In...
Ti6Al4V cranial prostheses in the form of patterned meshes were 3D printed by selective laser melting an argon environment; using a CO2 source and micron-sized powder as starting material. The size shape chosen based on actual computer tomography images patient skull fractures supplied framework collaboration with neurosurgery clinic. After optimizations scanning speed parameters, material was defect-free (as shown metallographic analyses) chemically homogeneous, without elemental...
We report on biological-derived hydroxyapatite (HA, of animal bone origin) doped with lithium carbonate (Li-C) and phosphate (Li-P) coatings synthesized by pulsed laser deposition (PLD) onto Ti6Al4V implants, fabricated the additive manufacturing (AM) technique. After being previously validated in vitro cytotoxicity tests, Li-C Li-P 3D Ti implants were preliminarily investigated vivo, insertion into rabbits’ femoral condyles. The vivo experimental model for testing extraction force metallic...
In this study a continuous wave Ytterbium-doped Yttrium Aluminum Garnet (Yb: YAG) disk laser has been used for welding of AlMg3 casted alloy. A high-speed imaging camera employed to record hot vapor plume features during the process. The purpose was identify mechanism pores detection in real-time based on correlations between metallographic analyses and area/intensity various locations samples. formation especially position these had be kept under control order weld thick Based...
In the present paper marker structures consisting of W/Mo layers were deposited on bulk W samples by using a modified CMSII method. This technology, compared to standard CMSII, prevents formati ...
In the paper a comparative analyse of laser cladding behaviour metal-ceramic powder mixture was studied. The use In718 alloy as matrix material, with lower melting range than SS304, allowed reduction overheating layer, for same values of deposition parameters. At time, greater fluidity led to an increase in width cladded layer compared SS304 alloy. spherical alumina particles improvement appearance and adhesion substrate deposited layers. analysis results obtained metal composite (MMC)...
In this study, an application of the laser-melting deposition additive manufacturing technique as a welding method has been studied for laser (LW) AISI 304 stainless steel, specifically 0.4 mm and 0.5 thick sheets. The was carried out without with filler material. Inconel 718 powder particles were used material in second case. A series experiments designed by changing process parameters to identify effect operating conditions on weld width, depth, height. welds examined through...
Purpose Porosity is a commonly analyzed defect in the laser-based additive manufacturing processes owing to enormous thermal gradient caused by repeated melting and solidification. Currently, porosity estimation limited powder bed fusion. The needs be explored laser deposition (LMD) process, particularly analytical models that provide cost- time-effective solutions compared finite element analysis. For this purpose, study aims formulate two mathematical for deposited layer dimensions...
Abstract There has been an increased concern related to environmental pollution, caused by the emission of particles released during braking process. In future, safety laws will be increasingly restrictive and development new viable alternative technologies inherent. Because gray cast iron (GCI) a low cost mechanical properties compatible with this type application, it difficult identify similar material replace it. case vehicles that serve passenger transport, most convenient solution is...