scholarly journals Morphological and Crystallographic Effects in the Laser Powder-Bed Fused Stainless Steel Microstructure

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 672
Author(s):  
Tim Fischer ◽  
Leonhard Hitzler ◽  
Ewald Werner
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Crystallographic Texture ◽  
Experimental Studies ◽  
Grain Morphology ◽  
Steel Microstructure ◽  
Numerical Predictions ◽  
Anisotropic Mechanical Properties ◽  
The Individual ◽  
Individual Grains

One of the key aspects in additive manufacturing of stainless steels is the relationship between process parameters and the resulting microstructure. The selected process parameters typically cause a rapid solidification of the material, which leads to a microstructure that is highly textured both morphologically and crystallographically. While the morphological texture is characterised by a mainly columnar shape of the grains, the crystallographic texture is marked by a preferred grain orientation in the <001> direction (fibre texture). Due to the texture effects, pronounced anisotropic mechanical properties are present in the material. In this report, a series of virtual microstructures with different morphological and crystallographic features are generated to develop a fundamental understanding of the individual texture effects on the mechanical properties. The grain morphology is based on Voronoi tessellations, and the crystallographic texture is captured with crystal plasticity. Furthermore, the numerical predictions are compared with experimental studies. The mechanical properties predicted on the basis of the virtual microstructures show that the crystallographic effect is much more dominant than the morphology of the individual grains. Consistent with the experiments, the highest load-bearing capacity of the material occurs when the macroscopic loading acts under an angle of 45∘ to the preferred orientation of the crystals.

scholarly journals Control of Crystallographic Texture and Mechanical Properties of Hastelloy-X via Laser Powder Bed Fusion

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1064
Author(s):  
Shinya Hibino ◽  
Tsubasa Todo ◽  
Takuya Ishimoto ◽  
Ozkan Gokcekaya ◽  
Yuichiro Koizumi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Crystallographic Texture ◽  
Lamellar Microstructure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Hastelloy X ◽  
Single Crystalline ◽  
Powder Bed ◽  
Wide Range

The influence of various laser powder bed fusion (LPBF) process parameters on the crystallographic textures and mechanical properties of a typical Ni-based solid-solution strengthened alloy, Hastelloy-X, was examined. Samples were classified into four groups based on the type of crystallographic texture: single crystalline-like microstructure with <100>//build direction (BD) (<100>-SCM), single crystalline-like microstructure with <110>//BD (<110>-SCM), crystallographic lamellar microstructure (CLM), or polycrystalline microstructure (PCM). These four crystallographic textures were realized in Hastelloy-X for the first time here to the best of our knowledge. The mechanical properties of the samples varied depending on their texture. The tensile properties were affected not only by the Schmid factor but also by the grain size and the presence of lamellar boundaries (grain boundaries). The lamellar boundaries at the interface between the <110>//BD oriented main layers and the <100>//BD-oriented sub-layers of CLM contributed to the resistance to slip transmission and the increased proof stress. It was possible to control a wide range of crystallographic microstructures via the LPBF process parameters, which determines the melt pool morphology and solidification behavior.

scholarly journals A Comprehensive Review on Optimal Welding Conditions for Friction Stir Welding of Thermoplastic Polymers and Their Composites

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1208
Author(s):  
Syed Haris Iftikhar ◽  
Abdel-Hamid Ismail Mourad ◽  
Jamal Sheikh-Ahmad ◽  
Fahad Almaskari ◽  
S. Vincent
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Experimental Studies ◽  
High Quality ◽  
Friction Stir ◽  
Weld Joints ◽  
Superior Mechanical Properties ◽  
Influential Parameters

Friction stir welding (FSW) and friction stir spot welding (FSSW) techniques are becoming widely popular joining techniques because of their increasing potential applications in automotive, aerospace, and other structural industries. These techniques have not only successfully joined similar and dissimilar metal and polymer parts but have also successfully developed polymer-metallic hybrid joints. This study classifies the literature available on the FSW and FSSW of thermoplastic polymers and polymer composites on the basis of joining materials (similar or dissimilar), joint configurations, tooling conditions, medium conditions, and study types. It provides a state-of-the-art and detailed review of the experimental studies available on the FSW and FSSW between similar thermoplastics. The mechanical properties of FSW (butt- and lap-joint configurations) and FSSW weld joints depend on various factors. These factors include the welding process parameters (tool rotational speed, tool traverse speed, tool tilt angle, etc.), base material, tool geometry (pin and shoulder size, pin profile, etc.) and tool material, and medium conditions (submerged, non-submerged, heat-assisted tooling, cooling-assisted tooling). Because of the dependence on many factors, it is difficult to optimize the welding conditions to obtain a high-quality weld joint with superior mechanical properties. The general guidelines are established by reviewing the available literature. These guidelines, if followed, will help to achieve high-quality weld joints with least defects and superior mechanical properties. Apart from parametric-based studies, the statistical-based studies (e.g., analysis of variance (ANOVA)-based studies) are covered, which helps with the determination of the influential parameters that affect the FSW and FSSW weld joint strength. Also, the optimal ranges of the most influential process parameters for different thermoplastic materials are established. The current work on the development of general guidelines and determination of influential parameters and their operating ranges from published literature can help with designing smart future experimental studies for obtaining the global optimum welding conditions. The gaps in the available literature and recommendations for future studies are also discussed.

Integral Computer Model for Simulating Microstructure Evolution during Thermomechanical Processing and Heat Treatment of Steels and Predicting their Final Mechanical Properties

2021 ◽  
Vol 1016 ◽  
pp. 1532-1537
Author(s):  
Alexander Alexandrovich Vasilyev ◽  
Dmitry Sokolov ◽  
Semen Sokolov ◽  
N.G. Kolbasnikov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Model ◽  
Thermomechanical Processing ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Steel Structure ◽  
Chemical Compositions ◽  
Steel Microstructure ◽  
Physically Based

An integral computer model/program AusEvol Pro was developed to describe the evolution of steel microstructure during thermomechanical processing (hot rolling, forging), as well as subsequent heat treatment (normalization, tempering), and to evaluate the final mechanical properties (yield stress, tensile stress, elongation), hardness and impact toughness. The program implements a set of physically based models that allow quantitative description of all significant processes of steel structure formation with account of the effects of chemical composition both during thermomechanical processing and heat treatment. Calculations of the final mechanical properties are carried out using the developed models that take into account all physically meaningful contributions. The models created are verified both on the extensive database of our own experimental studies and on reliable data from literature for steels of various chemical compositions.

Role of the crystallographic texture in anisotropic mechanical properties of a newly-developed hot-rolled TRIP steel

2020 ◽  
Vol 790 ◽  
pp. 139683
Author(s):  
Shih-Che Chen ◽  
Cheng-Yao Huang ◽  
Yuan-Tsung Wang ◽  
Ching-Yuan Huang ◽  
Hung-Wei Yen
Keyword(s):  
Mechanical Properties ◽  
Crystallographic Texture ◽  
Trip Steel ◽  
Anisotropic Mechanical Properties ◽  
Hot Rolled

Effect of process parameters on tensile strength of FDM printed PLA part

2018 ◽  
Vol 24 (8) ◽  
pp. 1317-1324 ◽  
Author(s):  
Shilpesh R. Rajpurohit ◽  
Harshit K. Dave
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Process Parameters ◽  
Fused Deposition Modelling ◽  
Type I ◽  
Content Type ◽  
Layer Height ◽  
Fused Deposition ◽  
Anisotropic Mechanical Properties ◽  
Raster Angle

PurposeThe purpose of this paper to study the tensile strength of the fused deposition modelling (FDM) printed PLA part. In recent times, FDM has been evolving from rapid prototyping to rapid manufacturing where parts fabricated by FDM process can be directly used for application. However, application of FDM fabricated part is significantly affected by poor and anisotropic mechanical properties. Mechanical properties of FDM part can be improved by proper selection of process parameters.Design/methodology/approachIn the present study, three process parameter, namely, raster angle, layer height and raster width, have been selected to study their effect on tensile properties. Parts are fabricated as per ASTM D638 Type I standard.FindingsIt has been observed that the highest tensile strength obtained at 0° raster angle. Lower value of layer height is observed to be good for higher tensile strength because of higher bonding area between the layers. At higher value of raster width, tensile strength is improved up to certain extent after which presence of void reduces the tensile strength.Originality/valueIn the present investigation, layer height and raster width have been also varied along with raster angle to study their effect on the tensile strength of FDM printed PLA part.

Methodology of studying the mechanical properties of composite materials (reinforced concrete)

2018 ◽  
Vol 84 (12) ◽  
pp. 61-67
Author(s):  
V. A. Eryshev
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Analytical Relationship ◽  
Hardened Concrete ◽  
Deformation Model ◽  
Joint Work ◽  
Concrete Shrinkage ◽  
Axial Tension ◽  
Tension And Compression

The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.

Sign in / Sign up

Export Citation Format

Share Document