Benchmarking of print properties and microstructures of 316L stainless steel DMLS prints

2021 ◽  
Author(s):  
Lucas Gallant ◽  
Amy Hsiao ◽  
Grant McSorley
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Material Properties ◽  
316L Stainless Steel ◽  
Thermal Stresses ◽  
Mechanical Performance ◽  
Grain Structure ◽  
Direct Metal Laser Sintering ◽  
Metal Additive

Abstract Direct metal laser sintering (DMLS) is an established technology in metal additive manufacturing. This complex manufacturing process yields unique as-built material properties that influence mechanical performance and vary with different machine parameters. Part porosity and residual stresses, which lead to part failures, and grain structure, as it relates to mechanical properties and anisotropy of DMLS parts, require investigation for different print settings. This work presents results for density, residual stress, and microstructural inspections on designed test artifacts for the benchmarking of 3D metal printers. Results from printing artifacts on two separate DMLS printer models with default parameters show highly dense parts for both printers, with relative densities above 99.5%. Characterization of residual stress through cantilevered deflection specimens indicates similar resulting thermal stresses developed in both build processes, with deflection averages of 32.48% and 28.09% for the respective machines. Additionally, properties of the test artifact printed after adjusting default machine parameters for equal energy density are characterized.

Effect of Thermomechanical Processing on Grain Size, Texture and Mechanical Properties of Pure Magnesium

2020 ◽  
Vol 985 ◽  
pp. 97-108
Author(s):  
Mouhamadou Moustapha Sarr ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Stress ◽  
Thermomechanical Processing ◽  
Pure Magnesium ◽  
Grain Structure ◽  
Misorientation Distribution ◽  
Processed Material ◽  
Texture Characterization

This study aims to investigate the effect of processing routes (A and Bc) and temperature on microstructure, texture and mechanical properties of pure magnesium was studied in this research. An extruded pure magnesium (~99,9 %) was subjected to severe plastic deformation (SPD) by ECAP. Deformation was conducted at 523K and 473K and two different processing routes (A and Bc) were used to control the texture. The microstructure and texture characterization of the pressed materials were carried out. It was found that the microstructure displayed a bimodal grain structure after two passes and then became homogeneous after four passes following both routes A and Bc. The misorientation distribution was examined and the results revealed that the fraction of high angle grain boundaries (HAGB) was higher at temperature 473K. The texture was randomized following route Bc whereas it became strengthened in route A after four passes. According to the Hall-Petch (HP) relationship, the yield stress of polycrystalline metals increases with a decrease in grain size. In this study, a positive slope k was achieved in the strengthened texture while a negative one was obtained in the softened texture. The ductility of ECAP processed material was considerably improved (from 23% to 38%) without sacrificing the yield stress by route Bc at 423K.

Development of Residual Stress Improvement for Nuclear Pressure Vessel Instrumentation Nozzle Weld Joint (P-43+P-8) by Means of Induction Heating

2006 ◽  
Author(s):  
Takuro Terajima ◽  
Takashi Hirano
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Residual Stresses ◽  
Induction Heating ◽  
Weld Joint ◽  
Thermal Stresses ◽  
Pressure Vessels ◽  
Weld Joints

As a counter measurement of intergranular stress corrosion cracking (IGSCC) in boiling water reactors, the induction heating stress improvement (IHSI) has been developed as a method to improve the stress factor, especially residual stresses in affected areas of pipe joint welds. In this method, a pipe is heated from the outside by an induction coil and cooled from the inside with water simultaneously. By thermal stresses to produce a temperature differential between the inner and outer pipe surfaces, the residual stress inside the pipe is improved compression. IHSI had been applied to weld joints of austenitic stainless steel pipes (P-8+P-8). However IHSI had not been applied to weld joints of nickel-chromium-iron alloy (P-43) and austenitic stainless steel (P-8). This weld joint (P-43+P-8) is used for instrumentation nozzles in nuclear power plants’ reactor pressure vessels. Therefore for the purpose of applying IHSI to this one, we studied the following. i) Investigation of IHSI conditions (Essential Variables); ii) Residual stresses after IHSI; iii) Mechanical properties after IHSI. This paper explains that IHSI is sufficiently effective in improvement of the residual stresses for this weld joint (P-43+P-8), and that IHSI does not cause negative effects by results of mechanical properties, and IHSI is verified concerning applying it to this kind of weld joint.

scholarly journals Mechanical Properties of Steels for Cold-Formed Steel Structures at Elevated Temperatures

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Zhen Nie ◽  
Yuanqi Li ◽  
Yehua Wang
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Elevated Temperatures ◽  
Elasticity Modulus ◽  
Mechanical Performance ◽  
Strain Curve ◽  
Steel Structures ◽  
Test Method ◽  
Stress Relieving ◽  
Cold Formed Steel

It is highly important to clarify the high-temperature mechanical properties in the design of cold-formed steel (CFS) structures under fire conditions due to the unique deterioration feature in material properties under fire environment and associated reduction to the mechanical performance of members. This paper presents the mechanical properties of widely used steels for cold-formed steel structures at elevated temperatures. The coupons were extracted from original coils of proposed full annealed steels (S350 and S420, with nominal yielding strengths 280 MPa and 350 MPa) and proposed stress relieving annealed steels (G500, with nominal yielding strength 500 MPa) for CFS structures with thickness of 1.0 mm and 1.2 mm, and a total of nearly 50 tensile tests were carried out by steady-state test method for temperatures ranging from 20 to 700°C. Based on the tests, material properties including the yield strengths, ultimate strengths, the elasticity modulus, and the stress-strain curve were obtained. Meanwhile, the ductility of steels for CFS structures was discussed. Then, the temperature-dependent retention factors of yield strengths and elasticity modulus were compared to those provided by design codes and former researchers. Finally, a set of prediction equations of the mechanical properties for steels for CFS structures at elevated temperatures was proposed depending on existing tests data.

scholarly journals Study of the mechanical performance and analysis of hybrid natural snake grass-jute-glass fiber strengthened polyester composite

2017 ◽  
Vol 7 (1.1) ◽  
pp. 78
Author(s):  
C. Thiruvasagam ◽  
S. Prabagaran ◽  
P. Suresh
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Mechanical Performance ◽  
Microstructural Analysis ◽  
Fiber Composites ◽  
Polyester Composite ◽  
The Common ◽  
Special Category ◽  
Scanning Electron

The research paper involves fiber composites form a special category materials that are contributing to present swaping of manufactured  hybrid  which finds traditional and non traditional applications. The study explains which are accentuates and optimizing for the recently recognized snake grass standard materials. In this article, the prospecting performance characterization of SG fiber is selected and contrasted as per the ASTM standard. This study additionally manages the examination apply different phenomena of this stages in Jute and snake as fortifications utilized index ended a try. Experiments have been conducted on normal Filaments, snake grass, Glass Fiber and Jute to analyse their Mechanical properties. The common strands are orchestrated in the flat and vertical heading as transferred quality on all sides. Microstructural analysis of these hybrid composite is observed using Scanning  Electron Microscope that reveals bonding and Filament breaksge, Voids and Fiber decover which are further investigated.

Evaluation of Mechanical Properties of Regenerated Bone by Nanoindentation Technique

2010 ◽  
Vol 654-656 ◽  
pp. 2220-2224 ◽  
Author(s):  
Takuya Ishimoto ◽  
Takayoshi Nakano
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Bone Tissue ◽  
Material Properties ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Mechanical Tests ◽  
Long Bone ◽  
Nanoindentation Technique ◽  
Intact Bone

To evaluate the material parameters of regenerated bone, it is important to clarify the mechanical performance of the regenerated portion. In general, the shape and size of regenerated bone tissue is heterogeneous. It is often difficult to elucidate material properties by means of conventional mechanical tests such as compressive and/or tensile tests and bending tests. The nanoindentation technique has been utilized to evaluate the material properties of small or microstructured materials because they do not necessarily require a large well-designed specimen. Thus, this technique may be useful for the evaluation of the material properties of regenerated bone tissue. In this study, this technique was applied for the assessment of the Young’s modulus and hardness of regenerated and intact long bones of a rabbit. The regenerated bone exhibited a significantly lower Young’s modulus and hardness than the intact bone. The regenerated long bone also exhibited impaired mechanical properties, which may have been caused by the difference in the nano-organization of its collagen fibers and mineral crystals (the main components of bone tissue), from that of the intact bone.

Characterization of Mechanical Properties and Residual Stress in API 5L X80 Steel Welded Joints

2017 ◽  
Vol 27 (1) ◽  
pp. 124-137 ◽  
Author(s):  
Amilton de Sousa Lins ◽  
Luís Felipe Guimarães de Souza ◽  
Maria Cindra Fonseca
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Welded Joints ◽  
X80 Steel

Thermal Stresses in Materials with Temperature-Dependent Properties

1991 ◽  
Vol 44 (9) ◽  
pp. 383-397 ◽  
Author(s):  
Naotake Noda
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Metal Forming ◽  
Thermal Stresses ◽  
Main Theme ◽  
Thermal And Mechanical Properties ◽  
Temperature Dependent ◽  
Accurate Analysis ◽  
Thermoelastic Problems ◽  
Temperature Dependent Properties

The present review on thermal stresses in materials with temperature-dependent properties focuses on papers published after 1980. The thermal and mechanical properties in materials subjected to thermal loads due to high temperature, high gradient temperature, and cyclical changes of temperature are dependent on temperature. The main theme of the thermoelastic problems in materials and structures with temperature-dependent material properties is to establish analytical procedures to solve the governing differential equations. In the thermo-inelastic problems, however, we must perform more accurate analysis of the practical problems (weld, heat treatment, metal forming, etc) taking account of the temperature-dependent material properties by use of numerical procedures (finite element methods, mainly).

Residual Stress Assessment in the Al2O3\Mullite Based Laminated System

2007 ◽  
Vol 333 ◽  
pp. 243-246
Author(s):  
Lorenzo Micele ◽  
Mylene Brach ◽  
Francis Chalvet ◽  
Goffredo de Portu ◽  
Giuseppe Pezzotti
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Cross Section ◽  
Laminate Composite ◽  
Spectroscopic Characterization ◽  
Gradual Change ◽  
Laminated Structure ◽  
Stress Assessment ◽  
Residual Stress State

To improve mechanical properties of mullite, a mullite-Al2O3\mullite laminate composite was prepared. Lamination generates residual stresses within the structure, measured by piezospectroscopy. A preliminary and complete piezo-spectroscopic characterization of the Al2O3\mullite system was carried out. A method to determine the concentration of Al2O3 in the composite by Raman spectrum was proposed and used to assess the composition of the laminated structure along the cross section. The experimental results evidenced a gradual change of composition and residual stress state between the two layer.

Characterization of discontinuous carbon fiber liquid molded PA-6 composites via strategic placement of additional reinforcements

2018 ◽  
Vol 37 (22) ◽  
pp. 1335-1345 ◽  
Author(s):  
Siddhartha Brahma ◽  
Vikas Patel ◽  
Selvum Pillay ◽  
Haibin Ning ◽  
Vinoy Thomas
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Surface Area ◽  
Mechanical Characterization ◽  
Mechanical Performance ◽  
Total Surface Area ◽  
Sem Analysis ◽  
Average Increase ◽  
Similar Increase

The flexibility of processing PA6-based discontinuous carbon fiber panels using vacuum-assisted resin transfer molding was studied. The ease of incorporating various reinforcements namely baseline, tow in the center of preform, fabric in the center of preform and fabric on the outside as skin was investigated. Mechanical characterization was conducted on all the variations made. There was an average increase of about 3%, 20% and 47% in the tensile properties of tow in the center, fabric in the center and fabric on the outside as skin, respectively, as compared to the baseline. A similar increase in properties was noticed in its flexural and impact strength. The data showed a correlation between the mechanical properties and the total surface area of additional reinforcements used. As the surface area of the reinforcement increased, the mechanical properties increased as well. It also showed that reinforcements on the surface of the preform as a skin performed the best. DMA analysis showed the effect of reinforcement on the storage modulus and tan delta across temperatures ranging from 30°C to 150°C. SEM analysis showed that the fibers and the additional reinforcements were coated with PA6 which translated into consistent mechanical performance.

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