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Influence of Technological Parameters of Direct Laser Deposition Process on the Structure and Properties of Deposited Products from Alloy Ti-6Al-4V
摘要： The technology of direct laser deposition is the most promising for using in various industries. One of the most interesting areas for using this technology is an aviation industry. Due to their unique properties, titanium alloys are widely used in the aircraft industry for gas turbine engine components. In this paper, the effect of DLD process parameters on defect formation and structure is considered. The influence of energy density on the mechanical properties of parts is determined.
关键词： Direct Laser Deposition,additive manufacturing,mechanical properties,Titanium alloys
更新于2025-11-28 14:24:20
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Surface engineering of a titanium alloy for tribological applications by nanosecond-pulsed laser
摘要： In many applications, surface engineering is needed in order to overcome the poor wear properties of titanium alloys. A fiber laser was used in different operation modes for remelting a Ti6Al4V surface and subsequently smoothing it again, resulting in a smooth, glossy and crack-free surface. The laser treated surface was characterized by tribological experiments, nanoindentation and (transmission) electron microscopy and compared to samples treated by plasma nitridation and thermal oxidation. All surface treatments improved the tribological behavior of Ti6Al4V to different extents. Nanoindentation measurements showed no strict correlation of mechanical properties and tribological behavior. It is hypothesized that apart from mechanical properties, binding of titanium electrons by interstitials plays a role in the occurrence or absence of adhesive wear.
关键词： Titanium alloys,Surface engineering,Adhesive wear,Ti6Al4V
更新于2025-09-23 15:21:01
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Mapping the geometry of Ti-6Al-4V: From martensite decomposition to localized spheroidization during selective laser melting
摘要： The influence that complex component geometries can have on microstructure formation is investigated in a rocket engine impeller fabricated of a Ti-6Al-4V alloy by selective laser melting (SLM). The SLM melt pool monitoring, indicative of the component’s thermal history during processing, is linked to the bulk mapping of martensite decomposition obtained by high energy synchrotron X-ray diffraction. In addition to the martensitic and lamellar microstructures typically obtained during SLM of Ti-6Al-4V, spheroidization is identified to take place in the component’s down-skin regions. Grain boundary migration may contribute to the latter effect. Small recrystallized grains form along grain boundaries.
关键词： Titanium alloys,X-ray diffraction,Microstructure,Selective laser melting,Synchrotron radiation
更新于2025-09-19 17:13:59
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Comparison of Titanium Powders and Products Manufactured by the Direct Laser Deposition Method
摘要： Ti-6Al-4V powders from two different vendors and two different fraction were compared with respect to their microstructures, size-distributions, chemistries, surface appearances. In addition, the influence of these powders on the structure and properties of products manufactured by an additive direct laser deposition method were established. The main parameters that have a significant impact on the structure and properties of Ti-6Al-4V deposited parts were established.
关键词： Direct Laser Deposition,powder metallurgy,additive technologies,Ti-6Al-4V,titanium powders,titanium alloys,DLD
更新于2025-09-16 10:30:52
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Structure and Phase Composition of Ti-6Al-4V Samples Produced by Direct Laser Deposition
摘要： In this article had been carried out X-ray phase analysis of the samples obtained using direct laser deposition. Two groups of samples were studied: the first one was obtained with oscillation of laser radiation, the second one – without. The investigations have shown that in the process of direct laser deposition, the α+β phase is formed from a Ti-6Al-4V titanium alloy with oscillation of laser radiation.
关键词： high-speed direct laser deposition,titanium alloys,X-ray analysis,oscillations of laser radiation,Ti-6Al-4V alloy,microstructure
更新于2025-09-16 10:30:52
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Eliminating continuous grain boundary α phase in laser melting deposited near β titanium alloys by heat treatment
摘要： Continuous grain boundary α phase (αGB) is widely present in laser melting deposited near β and β titanium alloys, and it can lead to intergranular fracture and low ductility. Because of the preferential nucleation and growth of α phase at β grain boundaries, the continuous αGB cannot be effectively eliminated by traditional heat treatment. Thus, in this study, we develop a new heat treatment including beta solution + ultra-slow furnace heating up + traditional heat treatment, to eliminate continuous αGB in laser melting deposited Ti-5Al-5Mo-5V-1Cr-1Fe near β titanium alloy, and the microstructures and tensile properties are investigated. The results indicated that, after beta solution + normal heating up + traditional heat treatment, the continuous αGB still exists, and the elongation is still low about 7.5%. However, after beta solution + ultra-slow heating up + traditional heat treatment, there are almost no continuous αGB, and the elongation increases to 15.2%. The mechanism about the αGB formation during ultra-slow heating up process is simply revealed. Furthermore, this new heat treatment is also suitable to eliminate continuous αGB for laser melting deposited Ti17 alloy.
关键词： ductility,continuous grain boundary α phase,laser melting deposition,heat treatment,near β titanium alloys
更新于2025-09-12 10:27:22
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Numerical modelling and experimental validation of thermal history of titanium alloys in laser beam melting
摘要： During selective laser melting processes parts will heat up with each layer depending on the geometry and surrounding powder material. This leads to process boundary conditions that are not certainly defined and can induce unstable melt pool sizes. These will have an influence on surface roughness and dimensional accuracy. One way to deal with this is an individual adaptation of process parameters, but without knowing the exact thermal boundary conditions in each layer one will not be able to adapt the parameters properly. In this paper a model for prediction of the macroscopic temperature history is presented and experimentally calibrated. A sample with characteristic features like overhanging’s was designed. These samples were produced by selective laser melting and simultaneously monitored by an infrared camera to calibrate the boundary conditions of a numerical model. This lays the foundation for part individual adaption of process parameters to improve the quality of SLM parts.
关键词： Experimental Validation,Numerical Modelling,Titanium Alloys,SLM
更新于2025-09-12 10:27:22
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Stiffness and hardness gradients obtained by laser surface melting of an aged β-Ti alloy
摘要： Components with variable stiffness have been attracting interest because of their potential for use in biomedical implants. Here, a β-titanium alloy aged under different conditions was subjected to laser surface melting (LSM). The high cooling rate typical of LSM avoided α-phase precipitation in the fusion zone (FZ) and heat-affected zone (HAZ) as the α precipitates were solid-solutioned into the β phase, producing a surface layer with full β phase over the aged substrate and reduced stiffness and hardness. The decrease in stiffness occurred independently of the aging condition used while the decrease in hardness was greater for the sample aged at the lower temperature as this had finer precipitates. A route involving aging at this lower temperature and LSM is proposed for use when a graded material combining a less rigid surface with the original core stiffness and strength is required, as in orthopedic implants.
关键词： Laser processing,Graded materials,Elastic modulus,Titanium alloys
更新于2025-09-12 10:27:22
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The Effects of Feature Sizes in Selectively Laser Melted Ti-6Al-4V Parts on the Validity of Optimised Process Parameters
摘要： Ti-6Al-4V is a popular alloy due to its high strength-to-weight ratio and excellent corrosion resistance. Many applications of additively manufactured Ti-6Al-4V using selective laser melting (SLM) have reached technology readiness. However, issues linked with metallurgical di?erences in parts manufactured by conventional processes and SLM persist. Very few studies have focused on relating the process parameters to the macroscopic and microscopic properties of parts with di?erent size features. Therefore, the aim of this study was to investigate the e?ect of the size of features on the density, hardness, microstructural evolution, and mechanical properties of Ti-6Al-4V parts fabricated using a ?xed set of parameters. It was found that there is an acceptable range of sizes that can be produced using a ?xed set of parameters. Beyond a speci?c window, the relative density decreased. Upon decreasing the size of a cuboid from (5 × 5 × 5 mm) to (1 × 1 × 5 mm), porosity increased from 0.3% to 4.8%. Within a suitable size range, the microstructure was not signi?cantly a?ected by size; however, a major change was observed outside the acceptable size window. The size of features played a signi?cant role in the variation of mechanical properties. Under tensile loading, decreasing the gauge size, the ultimate and yield strengths deteriorated. This investigation, therefore, presents an understanding of the correlation between the feature size and process parameters in terms of the microscopic and macroscopic properties of Ti-6Al-4V parts manufactured using SLM. This study also highlights the fact that any set of optimized process parameters will only be valid within a speci?c size window.
关键词： additive manufacturing,microstructure,tensile behaviour,selective laser melting,titanium alloys,mechanical properties
更新于2025-09-12 10:27:22
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Titanium for Consumer Applications || Bone regeneration on implants of titanium alloys produced by laser powder bed fusion: A review
摘要： Bone regeneration on biomaterials is a topic of increased interest due to the possibility of creating implants that existing bone can attach to. Titanium alloys are very suitable for this purpose and have been proven to be biocompatible, while also having suitable mechanical properties [1]. Moreover, titanium alloys are one of the most widely investigated materials for metal additive manufacturing (AM), which means that custom-designed implants can be manufactured reliably by AM. The AM technology best suited to this is powder bed fusion; laser powder bed fusion (LPBF) in particular holds some advantages. In this chapter, we investigate the current state of the art for the production of pure Ti and Ti6Al4V implants by LPBF, focusing on the requirements and capabilities for osseointegration. The first section discusses bone architecture and requirements for bone implants in general, identifying different requirements for different types of implants, and describing the various bone growth processes in more detail. This is followed by a section on surface structuring; the surface morphology and chemistry strongly influence the initial stages of bone growth, making it critical to the success of such implants. The next section describes porous structures, also known as lattice structures, which allow bone in-growth and attachment. This section describes various requirements for such lattices (pore size, lattice design, etc.) in terms of bone growth and summarizes what has been achieved thus far. The following section describes the mechanical properties of titanium lattice structures of various types that have been produced by LPBF. The next two sections describe in detail successful in vitro and in vivo experiments, respectively, for bone growth on LPBF titanium alloys. Finally, a discussion section summarizes the current state of the art and highlights requirements for future research efforts.
关键词： Bone regeneration,Titanium alloys,Laser powder bed fusion,Additive manufacturing,Osseointegration
更新于2025-09-12 10:27:22