Thermal and microstructural analysis of laser-based directed energy deposition for Ti-6Al-4V and Inconel 625 deposits

Lia, Frederick; Park, Joshua Z.; Keist, Jayme S.; Joshi, Sanjay; Martukanitz, R. P.

doi:10.1016/j.msea.2018.01.060

Cited by 75 publications

(9 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most samples possess equiaxed grains in the building plane, and columnar grains in the scanning plane and traverse plane. This is similar with other reported results for AM-built Ti6Al4V [17,18,22]. However, some slight differences present in different samples.…”

Section: The Effective Laser Energysupporting

confidence: 93%

See 1 more Smart Citation

Influence of Effective Laser Energy on the Structure and Mechanical Properties of Laser Melting Deposited Ti6Al4V Alloy

Zhang

et al. 2020

Materials

View full text Add to dashboard Cite

The laser energy density (ED) is often utilized in many additive manufacturing (AM) processes studies to help researchers to further investigate the process-structure-property correlations of Ti6Al4V alloys. However, the reliability of the ED is still questionable. In this work, a specific empirical calculation equation of the effective laser energy (Ee), which is a dimensionless parameter in laser melting deposition (LMD) processing, was proposed based on the molten pool temperature. The linear regression results and the coefficient of determination prove the feasibility of the Ee equation, which indicates that Ee can more accurately reflect the energy-temperature correlations than the commonly used laser energy density (ED) equation. Additionally, Ti6Al4V components were fabricated by the LMD process with different Ee to investigate the influence of Ee on their structure and mechanical properties. Experimental results show that the detrimental columnar prior β meso-structure can be circumvented and the uniform α + β laths micro-structure can be obtained in LMD Ti6Al4V by a judicious combination of the process parameter (P = 2000 W, V = 12 mm/s, and F = 10.5 g/min) and Ee (7.98 × 105) with excellent tensile strength (1006 ± 25 MPa) and elongation (14.9 ± 0.6%). Overall, the present work provides an empirical calculation equation to obtain a clearer understanding of the influence of different process parameters and indicates the possibility to fabricate the Ti6Al4V alloy with excellent mechanical properties by parameter optimization in the LMD process.

show abstract

Section: The Effective Laser Energysupporting

confidence: 93%

“…The energy density concept was also introduced in the LMD process and the equations got some improvement in relative research studies. Lia et al [18] defined a relative equation about E D for LMD research studies, as shown in Equation (3).…”

Section: Introductionmentioning

confidence: 99%

Influence of Effective Laser Energy on the Structure and Mechanical Properties of Laser Melting Deposited Ti6Al4V Alloy

Zhang

et al. 2020

Materials

View full text Add to dashboard Cite

show abstract

“…Key past work that used in-situ monitoring of additive manufacturing to understand the fundamental physical interactions have highlighted how unique additive manufacturing is in comparison to conventional methods such as welding and casting due to its rapid solidification. In addition to in-situ monitoring of thermal profiles with infrared cameras 28,29 , two-wave pyrometers 30 and thermocouples 31 , researchers at Lawrence Livermore National Laboratory used ultra high speed imaging of laser powder bed fusion and found that vapor driven entrainment as opposed to widely believed recoil pressure led to particle spattering which could lead to defects in the component 32 . The first of its kind, in-situ high-speed X-ray imaging of laser-matter interaction in a powder bed system using the Advanced Photon Source at Argonne National Laboratory revealed the capability to monitor the real-time growth of the melt pool geometry and its resulting solidification rate, particle ejection speeds out of the melt pool of tens of meters per second, and key hole porosity formation within 50 μ s in a laser powder bed fusion system 33 .…”

Section: Introductionmentioning

confidence: 99%

In-situ high-speed X-ray imaging of piezo-driven directed energy deposition additive manufacturing

Wolff

Parab

et al. 2019

Sci Rep

115

View full text Add to dashboard Cite

Powder-blown laser additive manufacturing adds flexibility, in terms of locally varying powder materials, to the ability of building components with complex geometry. Although the process is promising, porosity is common in a built component, hence decreasing fatigue life and mechanical strength. The understanding of the physical phenomena during the interaction of a laser beam and powder-blown deposition is limited and requires in-situ monitoring to capture the influences of process parameters on powder flow, absorptivity of laser energy into the substrate, melt pool dynamics and porosity formation. This study introduces a piezo-driven powder deposition system that allows for imaging of individual powder particles that flow into a scanning melt pool. Here, in-situ high-speed X-ray imaging of the powder-blown additive manufacturing process of Ti-6Al-4V powder particles is the first of its kind and reveals how laser-matter interaction influences powder flow and porosity formation.

show abstract

“…For validation, the results of both the thermal model and the experiment are superimposed on a graph, and comparisons are drawn (as shown in Figure 9C ). Lia et al (2018) uniquely embedded a thermocouple within the printed structure to monitor temperature (see Figure 9D ) [88]. To quantify the model error for temperature, a node in the thermal model that is nearest to the actual thermocouple location is chosen, and the temperatures at each time point for the model are compared to the actual thermocouple reading.…”

Section: Experiment-based Model Verification and Validation Techniquesmentioning

confidence: 99%

“…(C) Typical temporal (temperature) curves illustrating a comparison between model and experimental data [76]. (D) Micrograph of an embedded Alumina thermocouple within a track of printed material, measuring temperatures during processing [88]. (E) Schematic of the hole drilling method with the resultant residual stresses shown [94].…”

Section: Figurementioning

confidence: 99%

Invited review article: Metal-additive manufacturing—Modeling strategies for application-optimized designs

Bandyopadhyay

Traxel

2018

Additive Manufacturing

128

View full text Add to dashboard Cite

Next generation, additively-manufactured metallic parts will be designed with application-optimized geometry, composition, and functionality. Manufacturers and researchers have investigated various techniques for increasing the reliability of the metal-AM process to create these components, however, understanding and manipulating the complex phenomena that occurs within the printed component during processing remains a formidable challenge—limiting the use of these unique design capabilities. Among various approaches, thermomechanical modeling has emerged as a technique for increasing the reliability of metal-AM processes, however, most literature is specialized and challenging to interpret for users unfamiliar with numerical modeling techniques. This review article highlights fundamental modeling strategies, considerations, and results, as well as validation techniques using experimental data. A discussion of emerging research areas where simulation will enhance the metal-AM optimization process is presented, as well as a potential modeling workflow for process optimization. This review is envisioned to provide an essential framework on modeling techniques to supplement the experimental optimization process.

show abstract

Thermal and microstructural analysis of laser-based directed energy deposition for Ti-6Al-4V and Inconel 625 deposits

Cited by 75 publications

References 20 publications

Influence of Effective Laser Energy on the Structure and Mechanical Properties of Laser Melting Deposited Ti6Al4V Alloy

Influence of Effective Laser Energy on the Structure and Mechanical Properties of Laser Melting Deposited Ti6Al4V Alloy

In-situ high-speed X-ray imaging of piezo-driven directed energy deposition additive manufacturing

Invited review article: Metal-additive manufacturing—Modeling strategies for application-optimized designs

Contact Info

Product

Resources

About