Effect of Interlayer Cooling Time, Constraint and Tool Path Strategy on Deformation of Large Components Made by Laser Metal Deposition with Wire

Laser metal deposition with wire (LMD-w) is a developing additive manufacturing (AM) technology that has a high deposition material rate and efficiency and is suitable for fabrication of large aerospace components. However, control of material properties, geometry, and residual stresses is needed before LMD-w technology can be widely adopted for the construction of critical structural components. In this study, we investigated the effect of interlayer cooling time, clamp constraints, and tool path strategy on part distortion and residual stresses in large-scale laser additive manufactured Ti-6Al-4V components using finite element method (FEM). The simulations were validated with the temperature and the distortion measurements obtained from a real LMD-w process. We found that a shorter interlayer cooling time, full clamping constraints on the build plates, and a bidirectional tool path with 180° rotation minimized part distortion and residual stresses and resulted in symmetric stress distribution.

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Fundamentals of Residual Stresses in Joints Between Dissimilar Materials

MRS Bulletin ◽

10.1557/s0883769400048910 ◽

1995 ◽

Vol 20 (1) ◽

pp. 37-39 ◽

Cited By ~ 20

Author(s):

B.H. Rabin ◽

R.L. Williamson ◽

S. Suresh

Keyword(s):

Residual Stresses ◽

Material Properties ◽

Critical Stress ◽

Failure Mechanisms ◽

Dissimilar Materials ◽

Free Edge ◽

Structural Components ◽

Failure Characteristics ◽

Stress Components ◽

Metal Joint

When a discontinuity in material properties exists across a bonded interface, stresses are generated as a result of any thermal or mechanical loading. These stresses significantly affect strength and failure characteristics and may be large enough to prevent successful fabrication of a reliable joint. The use of an interlayer material to successfully reduce mismatch stresses, thereby preventing joint failure or improving joint strength and reliability, requires knowledge of failure mechanisms and of the effects of interlayer properties on the critical stress components.The origin of residual stresses developed during cooling of a ceramic-metal joint from an elevated fabrication temperature is illustrated qualitatively in Figure 1. Away from edges, the in-plane (parallel to interface) stresses are typically compressive in the ceramic and tensile in the metal. These stresses can cause cracking perpendicular to the interface, leading to spalling or delamination failures. Such failures are frequently observed in thin-film and coating geometries. Where the interface intersects a free edge, large shear and axial (perpendicular to the interface) stresses are generated. The edge stresses are typically tensile within the ceramic and tend to promote crack propagation within the ceramic parallel and adjacent to the interface. This is the most commonly observed failure mode in bonded structural components.

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Prediction and validation of residual stresses generated during laser metal deposition of γ titanium aluminide thin wall structures

Materials Research Express ◽

10.1088/2053-1591/ab38ee ◽

2019 ◽

Vol 6 (10) ◽

pp. 106550 ◽

Cited By ~ 3

Author(s):

Mallikarjuna Balichakra ◽

Srikanth Bontha ◽

Prasad Krishna ◽

Vamsi Krishna Balla

Keyword(s):

Residual Stresses ◽

Titanium Aluminide ◽

Metal Deposition ◽

Thin Wall ◽

Laser Metal Deposition ◽

Wall Structures

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Experimental Investigation of Temperature Distribution during Wire-Based Laser Metal Deposition of the Al-Mg Alloy 5087

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.988 ◽

2018 ◽

Vol 941 ◽

pp. 988-994 ◽

Cited By ~ 3

Author(s):

Martin Froend ◽

Frederic E. Bock ◽

Stefan Riekehr ◽

Nikolai Kashaev ◽

Benjamin Klusemann ◽

...

Keyword(s):

Process Parameters ◽

Large Scale ◽

Substrate Material ◽

Metal Deposition ◽

Temperature Evolution ◽

Laser Metal Deposition ◽

Deposition Rates ◽

Excessive Heat ◽

Manufacturing Techniques ◽

The Individual

Wire-based laser metal deposition enables to manufacture large-scale components with deposition rates significant higher compared to powder-based laser additive manufacturing techniques, which are currently working with deposition rates of only a few hundred gram per hour. However, the wire-based approach requires a significant amount of laser power in the range of several kilowatts instead of only a few hundred watts for powder-based processes. This excessive heat input during laser metal deposition can lead to process instabilities such as a non-uniform material deposition and to a limited processability, respectively. Although, numerous possibilities to monitor temperature evolution during processing exist, there is still a lack of knowledge regarding the relationship between temperature and geometric shape of the deposited structure. Due to changing cooling conditions with increasing distance to the substrate material, producing a wall-like structure results in varying heights of the individual tracks. This presents challenges for the deposition of high wall-like structures and limits the use of constant process parameters. In the present study, the temperature evolution during laser metal deposition of AA5087 using constant process parameters is investigated and a scheme for process parameter adaptions in order to reduce residual stress induced componential distortions is suggested.

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Laminated Ceramic Structures within Alumina / YTZP System Obtained by Low Pressure Joining

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.333.219 ◽

2007 ◽

Vol 333 ◽

pp. 219-222 ◽

Cited By ~ 3

Author(s):

Jonas Gurauskis ◽

Antonio Javier Sanchez-Herencia ◽

Carmen Baudín

Keyword(s):

Finite Element Method ◽

Residual Stress ◽

Finite Element ◽

Residual Stresses ◽

Material Properties ◽

Layered Materials ◽

Processing Parameters ◽

Spectroscopic Technique ◽

Reinforcement Mechanism ◽

Laminated Structures

The production of multilayer ceramics by laminating stacked green ceramic tapes is one of the most attractive methods to fabricate layered materials. In this work, a new lamination technique was employed to obtain laminated ceramic structures in the aluminazirconia system with residual stress compression at the outer layers. This reinforcement mechanism would lead to ceramics with changed material properties and R-curve behaviour. The optimization of processing parameters for fabrication of defect free monolithic and laminated structures is described. The residual stresses developed in the laminated structures are discussed in terms of the results obtained from piezo-spectroscopic technique measurements and finite element method calculations.

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Numerical Simulation of the Thermal Behavior during Laser Metal Deposition Shaping Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.380-384.4327 ◽

2013 ◽

Vol 380-384 ◽

pp. 4327-4331

Author(s):

Kai Zhang ◽

Lei Wang ◽

Xin Min Zhang

Keyword(s):

Numerical Simulation ◽

Finite Element Method ◽

Thermal Behavior ◽

Fem Simulation ◽

Thermal Response ◽

Metal Deposition ◽

Process Time ◽

Laser Metal Deposition ◽

And Control ◽

Good Agreement

Laser Metal Deposition Shaping (LMDS) is an emerging manufacturing technique that ensures significant reduction of process time between initial design and final components. The fabrication of fully dense parts with appropriate properties using the LMDS process requires an in-depth understanding of the entire thermal behavior of the process. In this paper, the thermal behavior during LMDS was studied, both numerically and experimentally. Temperature distribution and gradient in the fabricated part were obtained by finite element method (FEM) simulation. The numerical results are in good agreement with the experimental observations. The numerical method contributes to the comprehension and control of the thermal behavior, and may be used to optimize process parameters and predict the thermal response of LMDS fabricated components.

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LMDCAM2: Software Tool for Near-Net Repair, Cladding and Built-Up by Laser Metal Deposition

Volume 1: Processing ◽

10.1115/msec2015-9243 ◽

2015 ◽

Cited By ~ 1

Author(s):

John Flemmer ◽

Norbert Pirch ◽

Fabian Drinck

Keyword(s):

Tool Path ◽

Laser Scanner ◽

Software Tool ◽

Metal Deposition ◽

Design Stage ◽

Laser Metal Deposition ◽

Tool Paths ◽

Wide Range ◽

Subtractive Manufacturing ◽

Manufacturing Applications

Laser Metal Deposition (LMD) is growing in importance as a technique for the processing and manufacturing of parts in industry. LMD is used for a wide range of applications including the repair of worn parts, the built-up of 3D structures and the surface functionalization trough cladding. In many cases, the nominal CAD model from the design stage is no longer suitable for the representation of the part geometry due to distortion or defects especially in case of a worn part. This means for the generation of close contoured tool paths it is essential to create a digital model representing the surface of the actual part. This digitalization is often achieved by using a laser scanner whose raw output is represented by point cloud. Tool path planning software (CAM) available on the market generally demonstrate substantial deficits in generating paths on scanned surface data, because these programs are usually optimized on NURBS based surfaces and in most cases were originally designed for subtractive manufacturing applications. LMDCAM2 represents a new software tool especially designed for the LMD process. It is optimized for working with 3D scanned, triangulated data based models which could include noisy data and offers fundamental features for creating and manipulating tool paths adapted to the LMD process. Besides algorithms for calculating close contoured equidistant tracks, the software is also able obtain tracks for additive production through advanced slicing techniques of a 3D model.

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Crack Detection during Laser Metal Deposition by Infrared Monochrome Pyrometer

Materials ◽

10.3390/ma13245643 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5643

Author(s):

Yin Wu ◽

Bin Cui ◽

Yao Xiao

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Real Time ◽

Large Scale ◽

Crack Detection ◽

Crack Depth ◽

Metal Deposition ◽

Advanced Technology ◽

Laser Metal Deposition ◽

316L Austenitic Stainless Steel

Laser metal deposition (LMD) is an advanced technology of additive manufacturing which involves sophisticated processes. However, it is associated with high risks of failure due to the possible generation of cracks and bubbles. If not identified in time, such defects can cause substantial losses. In this paper, real-time monitoring of LMD samples and online detection of cracks by an infrared monochrome pyrometer (IMP) could mitigate this risk. An experimental platform for crack detection in LMD samples was developed, and the identification of four simulated cracks in a 316L austenitic stainless-steel LMD sample was conducted. Data at temperatures higher than 150 °C were collected by an IMP, and the results indicated that crack depth is an important factor affecting the peak temperature. Based on this factor, the locations of cracks in LMD-316L austenitic stainless-steel samples can be determined. The proposed technique can provide real-time detection of cracks through layers of cladding during large-scale manufacturing, which suggests its relevance for optimizing the technological process and parameters, as well as reducing the possibility of cracks in the LMD process.

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ADIMEW Test: Assessment of a Cracked Dissimilar Metal Weld Assembly

Flaw Evaluation, Service Experience, and Materials for Hydrogen Service ◽

10.1115/pvp2004-2542 ◽

2004 ◽

Author(s):

John B. Wintle ◽

Bridget Hayes ◽

Martin R. Goldthorpe

Keyword(s):

Residual Stresses ◽

Material Properties ◽

Nuclear Power ◽

Large Scale ◽

Research Programme ◽

Element Analysis ◽

Dissimilar Metal ◽

Four Point Bending ◽

Dissimilar Metal Weld ◽

Metal Weld

ADIMEW (Assessment of Aged Piping Dissimilar Metal Weld Integrity) was a three-year collaborative research programme carried out under the EC 5th Framework Programme. The objective of the study was to advance the understanding of the behaviour and safety assessment of defects in dissimilar metal welds between pipes representative of those found in nuclear power plant. ADIMEW studied and compared different methods for predicting the behaviour of defects located near the fusion boundaries of dissimilar metal welds typically used to join sections of austentic and ferritic piping operating at high temperature. Assessment of such defects is complicated by issues that include: severe mis-match of yield strength of the constituent parent and weld metals, strong gradients of material properties, the presence of welding residual stresses and mixed mode loading of the defect. The study includes the measurement of material properties and residual stresses, predictive engineering analysis and validation by means of a large-scale test. The particular component studies was a 453mm diameter pipe that joins a section of type A508 Class 3 ferritic pipe to a section of type 316L austentic pipe by means of a type 308 austentic weld with type 308/309L buttering laid on the ferritic pipe. A circumferential, surface-breaking defect was cut using electro discharge machining into the 308L/309L weld buttering layer parallel to the fusion line. The test pipe was subjected to four-point bending to promote ductile tearing of the defect. This paper presents the results of TWI contributions to ADIMEW including: fracture toughness testing, residual stress measurements and assessments of the ADIMEW test using elastic-plastic, cracked body, finite element analysis.

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