Microstructure and Mechanical Properties of Ti-6Al-4V Parts Fabricated by Laser Engineered Net Shaping

2015 ◽  
Author(s):  
Allen Bagheri ◽  
Nima Shamsaei ◽  
Scott M. Thompson
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Process Parameters ◽  
Melting Process ◽  
Traverse Speed ◽  
Metal Powders ◽  
Laser Engineered Net Shaping ◽  
Direct Laser ◽  
Elongation To Failure ◽  
Net Shaping

Laser Engineered Net Shaping (LENS®) is a Direct Laser Deposition (DLD) additive manufacturing technology that can be used for directly building complex 3D components from metal powders in a combined deposition/laser-melting process. In this study, the effect of LENS process parameters, such as laser power, powder feed rate and traverse speed, on the resultant microstructure, hardness and tensile strength of Ti-6Al-4V components is experimentally investigated. Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) are used to characterize the microstructure in terms of grain size and morphology. Relationships between process parameters and the microstructural/mechanical properties are provided. Results indicate that the scale of columnar grains increases with slower laser traverse speeds while other process parameters are maintained constant. The size of the α and β laths increases with higher laser powers and slower traverse speeds. The ultimate tensile and yield strengths of the LENS specimens were found to be higher than those of cast and wrought materials, and this can be generally attributed to the different cooling rates inherent to LENS — which impacts grain size. The percent elongation to failure, however, was consistently lower than that of the wrought material.

scholarly journals The Influence of Layer Thickness on the Microstructure and Mechanical Properties of M300 Maraging Steel Additively Manufactured by LENS® Technology

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 603
Author(s):  
Natalia Rońda ◽  
Krzysztof Grzelak ◽  
Marek Polański ◽  
Julita Dworecka-Wójcik
Keyword(s):  
Mechanical Properties ◽  
Layer Thickness ◽  
Maraging Steel ◽  
Structural Integrity ◽  
Tensile Tests ◽  
Dendritic Microstructure ◽  
Fine Grained ◽  
Laser Engineered Net Shaping ◽  
Microstructure And Mechanical Properties ◽  
Net Shaping

This work investigates the effect of layer thickness on the microstructure and mechanical properties of M300 maraging steel produced by Laser Engineered Net Shaping (LENS®) technique. The microstructure was characterized using light microscopy (LM) and scanning electron microscopy (SEM). The mechanical properties were characterized by tensile tests and microhardness measurements. The porosity and mechanical properties were found to be highly dependent on the layer thickness. Increasing the layer thickness increased the porosity of the manufactured parts while degrading their mechanical properties. Moreover, etched samples revealed a fine cellular dendritic microstructure; decreasing the layer thickness caused the microstructure to become fine-grained. Tests showed that for samples manufactured with the chosen laser power, a layer thickness of more than 0.75 mm is too high to maintain the structural integrity of the deposited material.

Paradox of Strength and Ductility in Metals Processed Bysevere Plastic Deformation

2002 ◽  
Vol 17 (1) ◽  
pp. 5-8 ◽  
Author(s):  
R. Z. Valiev ◽  
I. V. Alexandrov ◽  
Y. T. Zhu ◽  
T. C. Lowe
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
High Strength ◽  
High Ductility ◽  
Elongation To Failure ◽  
Failure Ductility ◽  
Strength And Ductility

It is well known that plastic deformation induced by conventional forming methodssuch as rolling, drawing or extrusion can significantly increase the strength of metalsHowever, this increase is usually accompanied by a loss of ductility. For example, Fig.1 shows that with increasing plastic deformation, the yield strength of Cu and Almonotonically increases while their elongation to failure (ductility) decreases. Thesame trend is also true for other metals and alloys. Here we report an extraordinarycombination of high strength and high ductility produced in metals subject to severeplastic deformation (SPD). We believe that this unusual mechanical behavior is causedby the unique nanostructures generated by SPD processing. The combination ofultrafine grain size and high-density dislocations appears to enable deformation by newmechanisms. This work demonstrates the possibility of tailoring the microstructures ofmetals and alloys by SPD to obtain both high strength and high ductility. Materialswith such desirable mechanical properties are very attractive for advanced structuralapplications.

Ultrasonic Vibration-Assisted Laser Engineered Net Shaping of Inconel 718 Parts: Microstructural and Mechanical Characterization

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Fuda Ning ◽  
Yingbin Hu ◽  
Zhichao Liu ◽  
Xinlin Wang ◽  
Yuzhou Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Vibration ◽  
Inconel 718 ◽  
High Efficiency ◽  
Experimental Investigations ◽  
Laser Engineered Net Shaping ◽  
Average Grain Size ◽  
Fabrication Defects ◽  
Heterogeneous Microstructures ◽  
Net Shaping

Laser engineered net shaping (LENS) has become a promising technology in direct manufacturing or repairing of high-performance metal parts. Investigations on LENS manufacturing of Inconel 718 (IN718) parts have been conducted for potential applications in the aircraft turbine component manufacturing or repairing. Fabrication defects, such as pores and heterogeneous microstructures, are inevitably induced in the parts, affecting part qualities and mechanical properties. Therefore, it is necessary to investigate a high-efficiency LENS process for the high-quality IN718 part fabrication. Ultrasonic vibration has been implemented into various melting material solidification processes for part performance improvements. However, there is a lack of studies on the utilization of ultrasonic vibration in LENS process for IN718 part manufacturing. In this paper, ultrasonic vibration-assisted (UV-A) LENS process is, thus, proposed to fabricate IN718 parts for the potential reduction of fabrication defects. Experimental investigations are conducted to study the effects of ultrasonic vibration on microstructures and mechanical properties of LENS-fabricated parts under two levels of laser power. The results showed that ultrasonic vibration could reduce the mean porosity to 0.1%, refine the microstructure with an average grain size of 5 μm, and fragment the detrimental Laves precipitated phase into small particles in a uniform distribution, thus enhancing yield strength, ultimate tensile strength (UTS), microhardness, and wear resistance of the fabricated IN718 parts.

Microstructure and Mechanical Properties of Inconel718-NiCrAlY Composites Prepared by Laser Engineered Net Shaping

2018 ◽  
Vol 20 (4) ◽  
pp. 1701043 ◽  
Author(s):  
Guohui Zhang ◽  
Shuai Yan ◽  
Fangyong Niu ◽  
Guangyi Ma ◽  
Dongjiang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Engineered Net Shaping ◽  
Microstructure And Mechanical Properties ◽  
Net Shaping

Effect of selective laser melting process parameters on microstructural and mechanical properties of TiC–NiCr cermet

2020 ◽  
Vol 46 (18) ◽  
pp. 28749-28757 ◽  
Author(s):  
Atefeh Aramian ◽  
Zohreh Sadeghian ◽  
Seyed Mohammad Javad Razavi ◽  
Konda Gokuldoss Prashanth ◽  
Filippo Berto
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Melting Process ◽  
Laser Melting ◽  
Selective Laser Melting Process

scholarly journals Effect of Interlayer Cooling on the Preparation of Ni-Based Coatings on Ductile Iron

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 544
Author(s):  
Yuyu He ◽  
Yijian Liu ◽  
Jiquan Yang ◽  
Fei Xie ◽  
Wuyun Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Additive Manufacturing ◽  
Dilution Rate ◽  
Process Parameters ◽  
Ductile Iron ◽  
Storage Effect ◽  
Thickness Increase ◽  
Average Grain Size ◽  
Metal Additive

In metal additive manufacturing without interlayer cooling, the macro-size of the layer itself is difficult to control due to the thermal storage effect. The effect of interlayer cooling was studied by cladding Ni-based coatings on the substrate of ductile iron. The results show that under the same process parameters, compared with non-interlayer cooling deposition, the dilution rate is better, and the thickness increase of interlayer cooling deposition is more uniform, which is conducive to controlling the macro-size of the interlayer cooling deposition. Furthermore, interlayer cooling deposition has fewer impurities and more uniform microstructures. Moreover, the average grain size is refined and the dendrite growth is inhibited, which improves the mechanical properties of the coating. Therefore, the hardness of the interlayer cooling specimens is greater than that of the non-interlayer-cooled specimens.

scholarly journals Experimental Investigation and Optimization of the Semisolid Multicavity Squeeze Casting Process for Wrought Aluminum Alloy Scroll

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5278
Author(s):  
Yi Guo ◽  
Yongfei Wang ◽  
Shengdun Zhao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Squeeze Casting ◽  
Shrinkage Porosity ◽  
Optimal Process ◽  
Squeeze Pressure ◽  
Wrought Aluminum

Scroll compressors are popularly applied in air-conditioning systems. The conventional fabrication process causes gas and shrinkage porosity in the scroll. In this paper, the electromagnetic stirring (EMS)-based semisolid multicavity squeeze casting (SMSC) process is proposed for effectively manufacturing wrought aluminum alloy scrolls. Insulation temperature, squeeze pressure, and the treatment of the micromorphology and mechanical properties of the scroll were investigated experimentally. It was found that reducing the insulation temperature can decrease the grain size, increase the shape factor, and improve mechanical properties. The minimum grain size was found as 111 ± 3 μm at the insulation temperature of 595 °C. The maximum tensile strength, yield strength, and hardness were observed as 386 ± 8 MPa, 228 ± 5 MPa, and 117 ± 5 HV, respectively, at the squeeze pressure of 100 MPa. The tensile strength and hardness of the scroll could be improved, and the elongation was reduced by the T6 heat treatment. The optimal process parameters are recommended at an insulation temperature in the range of 595–600 °C and a squeeze pressure of 100 MPa. Under the optimal process parameters, scroll casting was completely filled, and there was no obvious shrinkage defect observed inside. Its microstructure is composed of fine and spherical grains.

scholarly journals Titanium Ti6Al4V alloy reinforced by the addition of nano yttria stabilized zirconia fabricated by selective additive manufacturing: microstructure and mechanical investigations

2020 ◽  
Vol 321 ◽  
pp. 03018
Author(s):  
Amine HATTAL ◽  
Madjid DJEMAI ◽  
Jean Jacques FOUCHET ◽  
Thierry CHAUVEAU ◽  
Brigitte BACROIX ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Mass Density ◽  
Martensite Phase ◽  
Compression Tests ◽  
Stabilized Zirconia ◽  
Powder Mixtures ◽  
Size Refinement ◽  
Heat Treated ◽  
Elongation To Failure

Additive manufactured Ti6Al4V reinforced with nano yttria-zirconia (nYSZ) parts were fabricated using selective laser melting technology (SLM). The as-received Ti6Al4V powder and two powder mixtures of Ti6Al4V mixed with several nYSZ contents (1wt% and 2.5wt%) were prepared and then SLM processed. Parts were further subjected to a stress relief heat treatment. Besides, hot isostatic pressure (HIP) was used in order to eliminate residual porosities. The pycnometer-based technique was used to measure the mass density. XRD and EBSD analysis were performed to investigate the influence of nYSZ additions on the microstructure and subsequent mechanical properties via microhardness and compression tests. It was found that addition of nYSZ increases the density of the reinforced parts and produces a fine α martensite phase. Besides, the grain size was refined compared to that of heat treated Ti6Al4V. As a consequence, a significant increase in both the hardness and the compressive strength for the reinforced Ti6Al4V were obtained while the elongation to failure was kept. These improved mechanical properties are discussed in relation to the effect of nYSZ addition, which includes latice distortions and strengthening from grain size refinement and/or α formation.

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