Ti 6Al 4V Research Articles

Effects of machining parameters, ultrasonic vibrations and cooling conditions on cutting forces and tool wear in meso scale ultrasonic vibrations assisted end-milling (UVAEM) of Ti–6Al–4V under dry, flooded, MQL and cryogenic environments – A statistical analysis

Ti–6Al–4V, an alloy of titanium has recently gained focus of research to overcome its machinability challenges. Miniaturization in devices has forced a shift towards micro and meso-scale machining. Sustainability and green manufacturing concepts have shifted focus in machining from cutting fluids towards modern cooling approaches to minimize or eliminate them. In present research, cutting forces & tool wear in Ultrasonic Vibrations Assisted End Milling of Ti–6Al–4V at meso-scale under Dry, Flooded, Minimum Quantity Lubrication & Cryogenic cooling have been analyzed to develop optimum machining parameters. Taguchi L16 orthogonal array was designed to perform experiments keeping Cutting Speed, Feed per tooth, Depth of cut, Ultrasonic vibrations amplitude & Cooling environment as inputs. ANOVA was used to analyze contribution ratios by these parameters towards cutting forces & tool wear. Results indicated that machining conditions, cooling environment and Ultrasonic Vibrations influence cutting forces & tool wear. Depth of cut had the highest influence with 63.41% contribution towards cutting forces while cutting speed remained the highest influencing factor with 39.86% contribution towards tool wear. Cutting forces were reduced by 33.49%, 16.93% and 4.91% while tool wear was reduced by 26.43%, 9.48% and 5.17% under Minimum Quantity Lubrication environment compared to dry, flooded and cryogenic cooling respectively. Cutting forces and tool wear under ultrasonic vibrations were reduced by 24.52% and 13.16% respectively as compared to Conventional Machining (CM). For optimum results, Minimum Quantity Lubrication with low Cutting Speed, Depth of cut, Feed per tooth and high amplitude of ultrasonic vibrations is recommended to machine Ti–6Al–4V.

Hybrid manufacturing approach for landing gear applications: WAAM Ti–6Al–4V on forged Ti–5Al–5Mo–5V–3Cr

High-strength metastable β-titanium alloys like Ti-5553 (Ti–5Al–5Mo–5V–3Cr) are frequently used in highly loaded aerospace components. Such aerospace parts tend to be expensive to traditionally manufacture due to current industry process limitations such as inflexibility for complex geometries, costs related to tooling for large forgings, extended lead times, poor machinability and high material waste. These challenges are leading to increased interest in exploring alternative manufacturing routes. This work investigates the use of additive manufacturing to deposit cost-effective and machinable Ti-64 (Ti–6Al–4V) alloy onto a forged Ti-5553 alloy substrate. The microstructure evolution, microhardness and tensile properties have been investigated for both the as-deposited as well as for stress relief heat-treated conditions. The results confirmed the formation of coarse columnar β grains with a fine basketweave α structure. The heat affected zones (HAZs) developed in the Ti-5553 substrate material from the cyclic thermal fluxes introduced from the melt-pool were characterized by a gradient microstructure of dissolving constituent phases with nearing proximity to the fusion zone. Tensile testing in the as-deposited condition was characterised with a UTS of 884 MPa and a ductility of 15%. Tensile samples extracted across the substrate-deposit interface all failed in the WAAM Ti-64 material and demonstrated comparatively greater strength but poorer ductility. A band of tensile residual stresses was imparted along the substrate, but was adequately stress relieved after heat-treatment at 600 °C. The heat-treatment led to the formation of more homogeneous α-phase laths throughout the HAZ of the Ti-5553 material and provided overall improvements to the strength and ductility.

Improved low cycle fatigue property of Ti–6Al–4V alloy by trace Fe addition

The low-cycle fatigue properties of titanium alloys suffering cyclic loading determines the safety in service for their components used in submarine shells. It has been reported that tensile property could be improved by making use of Fe alloying element partitioning effect. However, the fatigue property and mechanism of titanium alloys with Fe addition remain unknown. In this study, the low-cycle fatigue property and cyclic deformation mechanism of Ti–6Al–4V-0.55Fe and Ti–6Al–4V ELI with a duplex microstructure were systematically investigated. With the addition of Fe element, Ti–6Al–4V-0.55Fe with longer lasting cyclic hardening behavior and lower cyclic softening rate, showed higher fatigue life under selected strain amplitudes. Under low strain amplitude, effect of Fe on dislocation motion, interface resistance, lattice distortion, and micro strain were responsible for the enhanced fatigue life. While under high strain amplitude, Fe brought out the pinning effect on interface. Besides, Fe addition also limited the fatigue crack propagation.

Eliminating cracks in Ti–47Al–2Cr–2Nb/Ti–6Al–4V micro-laminated composites fabricated by dual-material laser powder bed fusion

The low ductility of titanium aluminide at room temperature has been one of the factors that severely limit its applications. In this study, Ti–6Al–4V (Ti64) alloys were combined with Ti–47Al–2Cr–2Nb (TiAl) alloys to make micro-laminated composites with optimal ply configurations to eliminate crack formation in TiAl and improve the ductility. A dual-material laser powder bed fusion (LPBF) system was used to fabricate the TiAl/Ti64 micro-laminate samples. The presence of cracks, elemental composition and mechanical properties were experimentally characterised and analysed to understand the effect of ply configuration and the mechanism of eliminating cracks. It was found that smaller TiAl ply thickness and lower TiAl volume fraction result in fewer cracks formed in the micro-laminates. Elemental composition analysis reveals that the Al content in the first two powder layers (i.e., 200 μm thick in total) of a TiAl ply is reduced to 10%–35% due to the partial mixture of the TiAl ply and the proceeding Ti64 ply in the LPBF. The reduced Al content leads to combined α-Ti, β-Ti and α2-Ti3Al phases instead of γ-TiAl phases, thus eliminating the formation of cracks within the first 200 μm thick region of the TiAl ply. This study demonstrates that crack-free and dense TiAl/Ti6 micro-laminated composites can be produced with the TiAl ply thickness reduced to 200 μm and the TiAl volume fraction reduced to 25% (Ti64 ply thickness 400 μm). Ductility of the crack-free micro-laminates at room temperature is comparable to or even exceeds the properties of TiAl/Ti64-type laminates made by other manufacturing processes, which may imply good machinability. Note that further research is required to investigate the properties and applications of the micro-laminates at elevated temperatures.

Ultrasonic vibration-assisted electrical discharge machining of enclosed microgrooves with laminated electrodes

An enclosed microgroove is a vital surface microstructure that is difficult to prepare on the surfaces of difficult-to-machine electrically conductive materials using conventional methods. Electrical discharge machining (EDM) is suitable for this task. It is obtained primarily through layer-by-layer scanning EDM with micro-column electrodes or reciprocating EDM with foil electrodes. However, owing to the small cross-sectional size of the electrodes, a stable machining process is challenging to achieve, which seriously reduces the machining efficiency. To solve these problems, this study proposed ultrasonic vibration-assisted EDM using a laminated electrode possessed strong anti-interference properties for enclosed microgrooves. The effects of ultrasonic vibration on the EDM of microgrooves with single foil and laminated electrodes were investigated. The results show that ultrasonic vibration could improve the machining efficiency of the two types of electrodes and significantly improve the profile quality of the microgrooves prepared using laminated electrodes. When the amplitude was 3 μm and the frequency was 30 kHz, the bottom sidewall corner radius of microgrooves machined by brass foils in laminated electrodes was 28 μm, the width, depth, and roughness of microgrooves machined by copper foils in laminated electrodes were approximately 78 μm, 229 μm and 0.7 μm, the material removal rate was 0.0072 mm3/min. Based on the optimized parameters, inverted “convex” microgrooves with fine consistency were successfully prepared using laminated electrodes on Ti–6Al–4V alloy surfaces. The machining time was reduced by 40% for each microgroove compared with using the single foil electrode. This study provides a new method for preparing complex microgrooves.

Optimization of parameters and formulation of numerical model employing GRA–PCA and RSM approach for friction stir welded Ti–6Al–4V alloy joints

In this work, an endeavour was made to determine the impact of the tool’s shoulder diameter, pin profile, rotational and traverse speeds on the mechanical properties of the friction stir welded namely Ti–6Al–4 V alloy joints. A total of 21 experiments were carried out based on the central composite design (CCD) concept of response surface methodology (RSM). A quadratic regression based numerical model was formulated to ascertain the relationship amidst the parameters of FSW process and the mechanical properties of the fabricated Ti alloy joints. Analysis of variance (ANOVA) was employed to confirm the importance of parameters and their interactive impacts. Optimized process parameter combinations were ascertained by grey relation based analysis (GRA) was coupled together with principal component analysis (PCA), a hybrid based approach. Single score of GRG based response was determined and GRG scores were ranked for all experiments. 1st rank was attained by the experiment no. 20 possessing a GRG score of 2.9989. Optimized values of 25 mm shoulder diameter having a taper cylindrical pin geometry employed at a tool traverse speed of 40 mm min−1, rotational speed of 1400 rpm resulted in the generation of flaw free Ti alloy joint possessing a largest tensile strength of 809.8 MPa, yield strength of 778.7 MPa and percentage of elongation of 6.9%. SEM based fractography of Ti alloy joint specimens announced that taper cylindrical pin geometry along with 25 m shoulder diameter of employed tool have an inevitable part in generating frictional heat in ideal volumes and a perfect stirring action during FSW process.

Low-temperature superplastic deformation mechanism of ultra-fine grain Ti–6Al–4V alloy by friction stir processing

The ultra-fine grain Ti–6Al–4V alloy sheet was successfully achieved by friction stir processing (FSP). The low-temperature superplastic deformation mechanism of Ti–6Al–4V alloy under the strain rate of 3 × 10−4 s−1 at 600 °C was studied by scanning electron microscope, electron backscatter diffraction and superplastic tensile test. It is found that the grain size of Ti–6Al–4V alloy by FSP is refined from 7.48 μm to 0.82 μm, and there is no preferential crystallographic orientation of the uniform grain. After FSP, the β phase of the base material (BM) in the grain boundary is refined and homogenized. During the superplastic tensile processing, with the increase of strain, the grain is refined continuously, and the α→β phase transition is induced by the dislocations pile-up at the β grain boundary, and the content of β phase increases. The grain near the fracture was refined to 0.35 μm, and the stress concentration led to the formation of cavities near the β phase, which eventually caused the fracture. The dynamic recrystallization in superplastic tensile processing is mainly geometric dynamic recrystallization and discontinuous dynamic recrystallization. The elongation of superplastic tensile (1033%) is 19.7 times higher than that of BM (50%). The order of superplastic deformation mechanism in the low-temperature superplastic deformation of the ultra-fine grain Ti–6Al–4V alloy sheet is as follows: intragranular dislocation slip and diffusion, grain boundary sliding, and phase boundary sliding. Phase boundary sliding is the main deformation mechanism for low-temperature superplastic deformation.

Electrochemical processing of parts from Ti—6Al—4V alloy by additive manufacturing

The process of alignment of the initial microgeometry of samples obtained by the method of selective electron beam melting (EBM) by electrochemical etching in aqueous solutions of NaCl under current density 20, 30 and 40 A/cm2 was studied. The possibility of reducing the parameters Ra and Rz from the values of 35 and 180 µm, respectively, to the values of 7.2 and 33 µm during the electrolysis time of 40 s under galvanostatic conditions with the removal of the allowance of 210 µm is shown. Keywords:selective electron beam melting, surface roughness, high speed electrochemical dissolution katusha0112@yandex.ru, morgunov56@mail.ru, sbp47@mail.ru, iliaslusar42@yandex.ru, smsergei1@yandex.ru

Effect of process parameters on the mechanical behavior of Ti6Al4V alloys fabricated by laser powder bed fusion method

The parameters used in the production process in laser powder bed fusion (L-PBF) technology, one of the additive manufacturing methods, have a critical effect on the mechanical behavior and density properties of the product and can change the properties of the product. Therefore, this study examined the influence of laser power, scanning speed, hatch spacing and beam rotation angle on the tensile strength, impact energy, surface roughness, and porosity levels of Ti–6Al–4V produced through the L-PBF method. It was observed that the tensile strength changes directly proportional to the laser power. In addition, the tensile strength decreases significantly with a value of 645 MPa obtained at lowest 0.07 mm hatch spacing, 190 W laser power and 900 mm scanning speed. The lowest value of impact energy, with a value of 8.7 J, was reached at a rotation angle of 180°. It has been determined that surface roughness decreases significantly with increasing laser power, while it demonstrates an increase with higher scanning speeds. Surface roughness values of 8.9 μm parallel and 8.35 μm perpendicular to the building direction were achieved at a laser power level of 220 W. Laser power was identified as the most influential factor in determining the porosity ratio, with a high porosity rate 0.48% occurring at 160 W laser power. Furthermore, an increase in scanning speed resulted in a corresponding increase in the porosity rate.

Solid Particle Erosion Behaviour of Laser Sintered Heat Treated Ti–6Al–4V Alloy

Solid Particle Erosion Behaviour of Laser Sintered Heat Treated Ti–6Al–4V Alloy

Overload-induced anisotropy of fatigue crack growth in laser deposited Ti–6Al–4V alloy

Considering the anisotropy of microstructure of additive manufactured metal materials, quantitative assessment of the anisotropy of fatigue crack growth (FCG) behavior is necessary for structural damage tolerance design and evaluation. This study conducted an experimental and mechanistic investigation of the FCG behavior of the laser metal deposited (LMD) Ti–6Al–4V alloy, focusing on the anisotropy of FCG and the effect of overload on FCG. Both the FCG experiments with constant amplitude loading (CAL) and with a single overload (OL) were performed in different directions. Under CAL, the FCG rate exhibits a bilinear correlation with the stress intensity factor. Before the transition point (ΔKT = 16.9 MPa√m), since the grain boundaries are sparser along the columnar crystal growth direction, the FCG rate in the XY specimen is higher than that in the other directions. When the FCG rate further increases, the hindrance effect of grain boundaries on FCG weakens, and the anisotropy of FCG rates disappears. An interesting new finding is that when an overload is applied after ΔKT, the FCG rates in the XZ and ZX directions become different, and the overload-induced anisotropy increases with the overload ratio (OLR). The difference in FCG rates between the two directions exceeds 23.2% when OLR is 2.5. Based on microscopic and theoretical analysis, it was demonstrated that the overload induces residual strain in front of the crack-tip and enhances FCG resistance. The FCG resistance is positively related to the size of the plastic zone and negatively related to the yield strength in the loading direction.

Effect of heat treatment on microstructures and properties of vacuum laser welding Ti–6Al–4V titanium alloy

Vacuum laser welding of titanium alloys is currently being explored for use in UAVs and military-related fields, but the impact of post-weld heat treatment has been seldom studied. In this paper, the Ti–6Al–4V titanium alloy was welded by vacuum laser welding(VLW)with IPG 50 kW fiber laser, and analyze the microstructure and properties of the welds in as-welded state and post-welding heat treatment (850 °C/2h/FC(FC:furnace cooling)and 980 °C/10min/FC+720 °C/2h/FC).The results show that the microstructure of the as-welded weld is composed of primary columnar crystal (primary β phase) and grain boundary martensite (α′), and the microstructure of primary columnar crystal is composed of α'+ (α'+β). The proportion of high-angle grain boundary(HAGB) is 92.3%. The tensile strength is 1009 MPa, and the elongation is 9.3%. The average impact toughness at room temperature is 13J. The weld microstructure at 850 °C/2h/FC is composed of the acicular α phase and the α+β between the acicular α phases, the primary columnar crystals basically disappear, and the acicular α phases criss-cross weave into the net basket structure.The proportion of HAGB is 97.4%.The tensile strength is 988.3 MPa,and the elongation is 14.8%. The average impact toughness is 17J. The microstructure of the weld at 980 °C/10min/FC+720 °C/2h/FC is composed of the coarser acicular α phase and the (α+β) between the coarser acicular α phases. The proportion of HAGB is about 83.2%. The tensile strength is 586 MPa, and the elongation is 1.6%. The average impact toughness is 1.4J.

Microstructural effects on the rotating bending fatigue behavior of Ti–6Al–4V produced via laser powder bed fusion with novel heat treatments

The rotating bending fatigue (RBF) behavior (fully reversed, R = −1) of additively manufactured (AM) Ti–6Al–4V alloy produced via laser powder bed fusion (PBF-L) was investigated with respect to different microstructures achieved through novel heat treatments. The investigation herein seeks to elucidate the effect of microstructure by controlling variables that can affect fatigue behavior in Ti–6Al–4V, such as chemistry, porosity, and surface roughness. In order to control these variables, different hot isostatic pressing (HIP) treatments at 800 °C, 920 °C, and 1050 °C with a 920 °C temper were applied to three sets of Ti–6Al–4V cylinders that originated from the same PBF-L build, such that there were 30 tests per condition. After HIP treatment, the specimens were machined and tested. The highest runout stress was achieved after sub-β transus HIP at 800 °C for 2 h at 200 MPa of pressure. A significant drop in fatigue strength was attributed to large prior-β grains and grain boundary α resulting from super-β transus HIP treated specimens. For the sub-β transus HIP specimens, differences in fatigue strength were attributed to α lath thickness, relative dislocation density, and dislocation boundary strengthening.

Vapor chemical composition in electron beam powder bed fusion using Ti–6Al–4V powder

Vapor chemical composition in electron beam powder bed fusion using Ti–6Al–4V powder

Laser-inherent porosity defects in additively manufactured Ti–6Al–4V implant: Formation, distribution, and effect on fatigue performance

Porosity defects are inherently present in Ti–6Al–4V (Ti6-4) parts produced using additive manufacturing (AM) methods like laser powder-bed fusion (LPBF). This work aims to investigate different laser-inherent porosity defects at various LPBF parameter settings and assess their impact on the fatigue behaviour of Ti6-4 implants processed by LPBF. The presence of LPBF-inherent porosity defects with different shapes and sizes was established using microstructural examination and X-ray micro-CT analysis. These mostly comprise lack-of-fusion porosity (LoFP), gas-entrapped porosity (GeP), and pores-induced microcracks. Volumetric porosity defects were seen to range from 1.9 × 104 to 9.52 × 105 μm3. The L-1 specimen exhibited the lowest defect, while the L-6 specimen displayed the largest number of defects. While LoFP defects predominate in L-6, there was a notable presence of GeP defects in the specimens processed using the factory default condition (L-D). Upon examination of the majority of specimens, GeP and LoFP coalesced to form clusters, leading to the formation of pores-induced microcracks. This ultimately leads to a decrease in fatigue performance. By maintaining the power at the default setting and increasing the scan speed by 8% of the default value, a specimen (L-1) with minimal porosity defects and superior fatigue performance is achieved. L-6 exhibits defects with significant dimensions and irregular form. Consequently, it displays inferior fatigue characteristics.

Uniaxial deformation behaviors and mechanism of Ti–6Al–4V alloy with bi-oriented grains

It is of great importance to investigate the deformation and damage mechanisms of polycrystalline materials with soft crystal orientations, considering the soft grains are usually the fatigue crack initiation sites. In this study, a Ti–6Al–4V alloy fully consisted of <01 1‾ 0> and <1‾ 21‾ 0> α (soft) grains was prepared and its uniaxial deformation behavior was investigated. Interestingly, no significant asymmetry on the tension-compression yield strength was found in this alloy with bi-grain orientations, though mechanical asymmetry was generally found in the traditional Ti alloys with strong texture. After high temperature solution treatment, the preferred bi-orientations were retained and the asymmetry degree of yield strength did not change, showing an excellent stability in texture and mechanical performance. Deformation mechanisms during tension and compression were studied and discussed. This work provides a new understanding on the deformation and damage mechanisms in the grains with soft crystal orientations, and may guide the microstructural design of Ti alloy for pursuing high mechanical and fatigue performances in the future.

Microstructural effects and constitutive modelling of cyclic softening behaviour in Ti–6Al–4V titanium alloys

Cyclic softening in Ti–6Al–4V titanium alloy significantly influences the reliability and performance of critical engineering components. This study addresses the lack of a comprehensive understanding of cyclic softening in different microstructures of Ti–6Al–4V titanium alloys. Microstructures with bimodal and lamellar morphologies were prepared by heat treatment of Ti–6Al–4V titanium alloy at various temperatures. Interrupted low-cycle fatigue tests revealed a larger cyclic softening for the bimodal microstructures than the lamellar microstructures. Finite element analysis (FEA) captured the cyclic softening by incorporating the Voce isotropic hardening model with the Chaboche kinematic hardening model. Two nonlinear kinematic hardening terms, along with the Voce isotropic hardening model whose parameters were calculated using the variation in cyclic yield strength and cyclic stress amplitude resulted in good prediction for bimodal and lamellar microstructures, respectively. The accuracy of the model is further improved when a linear kinematic term is added to it. Transmission electron microscope, electron backscatter diffraction, and energy dispersive spectroscopy analysis revealed that the extensive softening in the bimodal microstructure is associated with the dislocation localization in the primary alpha (αp) leading to a considerable plastic strain accumulation and subsequent crystal re-orientation. The alloying element partitioning, lamella width, and the ease of slip transmission at the secondary alpha (αs) and beta (β) interface also play essential roles in the cyclic softening.

Corrosion mechanism of potassium silicate coating on Ti–6Al–4V alloys under solid NaCl deposit at 700 °C

A potassium silicate coating cured by calcium hydrogen phosphate was prepared on Ti–6Al–4V, and its protection behavior against NaCl-induced corrosion was investigated at 700 °C for 500 h by the means of thermogravimetry, SEM, EMPA, XRD and TEM. The bare Ti–6Al–4V alloy suffered severe corrosion as the thickness of corrosion production layer exceeded 2 mm after 500 h. The major corrosion production was TiO2, and sodium titanates was observed within 100 h while disappeared after long-term tests. Accordingly, a novel model for NaCl-induced corrosion of Ti alloys at high temperatures was proposed. That is, the porosity of the corrosion product is strongly correlated with the reaction between water vapor in air and sodium titanates at high temperatures. The coating exhibited excellent protection as the corroded substrate layer, which is Ti5Si3 resulted from coating-substrate reaction, is ∼6.6 μm only, and no oxide scale was formed. Dissolution of Na in the coating was identified and is believed to be associated with the protective mechanism of the potassium silicate coating, i.e. this dissolution avoids chlorination-oxidation of Ti alloy.

Personalized feature extraction for manufacturing process signature characterization and anomaly detection

Manufacturing process signatures reflect the process stability and anomalies that potentially lead to detrimental effects on the manufactured outcomes. Sensing technologies, especially in-situ image sensors, are widely used to capture process signatures for diagnostics and prognostics. This imaging data is crucial evidence for process signature characterization and monitoring. A critical aspect of process signature analysis is identifying the unique patterns in an image that differ from the generic behavior of the manufacturing process in order to detect anomalies. It is equivalent to separating the “unique features” and process-wise (or phase-wise) “shared features” from the same image and recognizing the transient anomaly, i.e., recognizing the outlier “unique features”. In state-of-the-art literature, image-based process signature analysis relies on conventional feature extraction procedures, which limit the “view” of information to each image and cannot decouple the shared and unique features. Consequently, the features extracted are less interpretable, and the anomaly detection method cannot distinguish the abnormality in the current process signature from the process-wise evolution. Targeting this limitation, this study proposes personalized feature extraction (PFE) to decouple process-wise shared features and transient unique features from a sensor image and further develops process signature characterization and anomaly detection strategies. The PFE algorithm is designed for heterogeneous data with shared features. Supervised and unsupervised anomaly detection strategies are developed upon PFE features to remove the shared features from a process signature and examine the unique features for abnormality. The proposed method is demonstrated on two datasets (i) selected data from the 2018 AM Benchmark Test Series from the National Institute of Standards and Technology (NIST), and (ii) thermal measurements in additive manufacturing of a thin-walled structure of Ti–6Al–4V. The results highlight the power of personalized modeling in extracting features from manufacturing imaging data.

Research on microstructure and mechanical properties of Ti–6Al–4V ELI fabricated by hybrid directed energy deposition with in-situ rolling and annealing

To achieve superior damage tolerance and fatigue properties, it is desirable for the microstructure of Ti-6Al-4V ELI (Extra Low Interstitial) titanium alloy to consist of equiaxed grains with a homogeneous lamellar structure. However, traditional forging and single additive manufacturing techniques require extreme processes such as quasi β heat treatment and hot isostatic pressing. In this paper, a hybrid directed energy deposition method that integrates in-situ rolling with simple annealing is proposed to simultaneously achieve these microstructures. The results indicate that the initial microstructures produced by hybrid directed energy deposition consist of fine equiaxed prior-β grains, inconspicuous interpass bright bands, randomly oriented lamellar structure and numerous small substructures at the TEM scale. Due to the plastic deformation caused by in-situ rolling, the primary β grains underwent significant refinement with a reduction in grain diameter from over 2000 μm to 113.8 μm. Besides, the unique microstructures and thickness of α laths are influenced by coarsening and dissolution mechanisms that are controlled by diffusion during phase transformation. Furthermore, a uniform microstructure without bright bands and excellent comprehensive properties can be achieved through heating at 880 °C for 2 h and natural cooling. These findings validate that hybrid directed energy deposition coupled with simple annealing present a novel and cost-effective approach for the direct manufacturing of uniform titanium alloy forgings.