Solid Phase Sheet Forming of Thermoplastics—Part I: Mechanical Behavior of Thermoplastics to Yield

1986 ◽  
Vol 108 (2) ◽  
pp. 107-112 ◽  
Author(s):  
V. K. Stokes ◽  
H. F. Nied
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Solid Phase ◽  
Hold Time ◽  
Sheet Forming ◽  
Temperature Deformation ◽  
Polybutylene Terephthalate ◽  
Forming Process ◽  
Time Periods ◽  
Insight Into

The detailed mechanical behavior to yield of three thermoplastics—polycarbonate, polybutylene terephthalate, and polyetherimide—subjected to simulated forming histories, is examined in order to gain an insight into the sheet forming process for thermoplastics. The phenomenology of yield is shown to be quite different for semicrystalline polybutylene terephthalate when compared with amorphous polycarbonate and polyetherimide. The dependence of the mechanical properties of thermoplastics on temperature, deformation rate and hold-time periods are shown to be important for understanding and controlling the solid phase sheet forming process.

Solid Phase Sheet Forming of Thermoplastics—Part II: Large Deformation Post-Yield Behavior of Plastics

1986 ◽  
Vol 108 (2) ◽  
pp. 113-118 ◽  
Author(s):  
H. F. Nied ◽  
V. K. Stokes
Keyword(s):  
Solid Phase ◽  
Large Strain ◽  
Amorphous Polymers ◽  
Sheet Forming ◽  
Point Of View ◽  
Large Strains ◽  
Polybutylene Terephthalate ◽  
Forming Process ◽  
Yield Behavior ◽  
Stable Manner

This paper examines the phenomenology of the large strain, post-yield behavior of the three thermoplastics—polycarbonate, polybutylene terephthalate and polyetherimide—from the point of view of the sheet forming process. A photographic technique is utilized to measure the large nonhomogeneous strains observed in polymers. This technique makes possible the mapping of the strain field for flat specimens in the form of strain contours. Amorphous polymers polycarbonate and polyetherimide are shown to behave differently from semicrystalline polybutylene terephthalate. All three polymers are shown to neck in a stable manner, with the necked regions undergoing very large strains. The mechanical properties of the necked/drawn polymer are shown to be substantially different from the properties of the virgin polymer.

Effect of Annealing Treatment on Die Filling Rate of Mini Gear in Squeezing Forming Process

2017 ◽  
Vol 746 ◽  
pp. 108-113 ◽  
Author(s):  
Tsung Han Huang ◽  
Cho-Pei Jiang ◽  
Fedor V. Grechnikov ◽  
Yaroslav A. Erisov
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Hold Time ◽  
Annealing Treatment ◽  
Hardness Test ◽  
Filling Rate ◽  
Forming Process ◽  
H13 Steel ◽  
Β Phase ◽  
Die Filling

The aim of this research is to investigate the effect of annealing treatment on mechanical properties and deformability of titanium alloy to form mini gear in squeezing process. Diameter of experimental specimen was 5mm of Grade 2 Ti alloy. It was annealed with temperature in a range of 500 to 1000 °C, resulting in different initial grain sizes. The mechanical properties and hardness of annealed specimens were obtained by means of tensile and micro-hardness test. In addition, a modulus of mini gear die was 0.92 and made of h13 steel. The annealed specimens were inserted in die and squeezed into mini gear. The experimental results show that microstructure of α-phase precipitates when annealing temperature reaches to 600 °C and hold time was 3 hours. The specimen which annealed with a temperature of 700 °C has the maximal elongation and die filling rate. The microstructural of β-phase precipitates when annealing temperature reaches to 1000 °C resulting in brittle behavior and the lowest die-filling rate.

Mechanical Properties of Biological Nanocomposite Nacre: Multiscale Modeling and Experiments on Nacre from Red Abalone

2005 ◽  
Vol 898 ◽  
Author(s):  
Pijush Ghosh ◽  
Devendra Verma ◽  
Bedabibhas Mohanty ◽  
Kalpana S Katti ◽  
Dinesh R Katti
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Multiscale Modeling ◽  
Experimental Studies ◽  
Weight Percent ◽  
Major Constituent ◽  
Red Abalone ◽  
Modeling And Experiments ◽  
Dynamics Simulations ◽  
Insight Into

AbstractNacre, the inner iridescent layer of mollusks shell is a bio-nanocomposite with the mineral aragonite as a major constituent and 2-5% of organics mainly in the form of proteins. Our multiscale modeling and experimental studies reveal that the microstructure and the small weight percent of organics are the key parameters attributed to the extreme toughness of nacre. We report that the presence of platelet interlocks nacre have a significant role in the enhancement of mechanical properties. Molecular simulation study is conducted to understand the behavior of aragonite-organic interface. The mechanical behavior of organics and inorganics in presence of each other is described using steered molecular dynamics simulations. This provides some understanding on the deformation mechanisms of the protein present between the aragonite layers. Our nanoindentation results indicate that the elastic modulus and hardness of nacre decreases as it is exposed to a denaturing temperature for proteins. The changes in the organic inorganic interaction have been experimentally described using Fourier Transform Infrared Spectroscopy. This work gives insight into the contribution of the various factors existing at different length scales on the overall mechanical behavior of nacre.

MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

2015 ◽  
Vol 10 (2) ◽  
pp. 2753-2761
Author(s):  
Saad El Madani ◽  
S. ELHAMZI ◽  
A. IBNLFASSI ◽  
L. ZERROUK ◽  
O. BEN LENDA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Solidification Process ◽  
Traitement Thermique ◽  
Homogenization Process ◽  
Fundamental Reason ◽  
Segregation Phenomenon ◽  
Proprietes Mecaniques ◽  
Cooling Velocity ◽  
Copper Effect

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements.   The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process.

Effects of Vickers Cracks on the Mechanical Properties of Solid-phase-sintered Silicon Carbide Ceramics

2012 ◽  
Vol 27 (9) ◽  
pp. 965-969
Author(s):  
Xiao YANG ◽  
Xue-Jian LIU ◽  
Zheng-Ren HUANG ◽  
Gui-Ling LIU ◽  
Xiu-Min YAO
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Solid Phase ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

scholarly journals Production and Processing of a Spherical Polybutylene Terephthalate Powder for Laser Sintering

2019 ◽  
Vol 9 (7) ◽  
pp. 1308 ◽  
Author(s):  
Rob Kleijnen ◽  
Manfred Schmid ◽  
Konrad Wegener
Keyword(s):  
Mechanical Properties ◽  
Thermal Processing ◽  
Selective Laser Sintering ◽  
Spherical Shape ◽  
Laser Sintering ◽  
Polybutylene Terephthalate ◽  
Powder Production ◽  
Injection Molded ◽  
Continuous Extrusion ◽  
Matrix Powder

This work describes the production of a spherical polybutylene terephthalate (PBT) powder and its processing with selective laser sintering (SLS). The powder was produced via melt emulsification, a continuous extrusion-based process. PBT was melt blended with polyethylene glycol (PEG), creating an emulsion of spherical PBT droplets in a PEG matrix. Powder could be extracted after dissolving the PEG matrix phase in water. The extrusion settings were adjusted to optimize the size and yield of PBT particles. After classification, 79 vol. % of particles fell within a range of 10–100 µm. Owing to its spherical shape, the powder exhibited excellent flowability and packing properties. After powder production, the width of the thermal processing (sintering) window was reduced by 7.6 °C. Processing of the powder on a laser sintering machine was only possible with difficulties. The parts exhibited mechanical properties inferior to injection-molded specimens. The main reason lied in the PBT being prone to thermal degradation and hydrolysis during the powder production process. Melt emulsification in general is a process well suited to produce a large variety of SLS powders with exceptional flowability.

scholarly journals Experimental and Numerical Evaluation of Mechanical Properties of 3D-Printed Stainless Steel 316L Lattice Structures

2021 ◽  
Author(s):  
M. Carraturo ◽  
G. Alaimo ◽  
S. Marconi ◽  
E. Negrello ◽  
E. Sgambitterra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Mechanical Behavior ◽  
Numerical Simulations ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Lattice Structures ◽  
Stainless Steel 316L ◽  
Research Attention ◽  
Octet Truss

AbstractAdditive manufacturing (AM), and in particular selective laser melting (SLM) technology, allows to produce structural components made of lattice structures. These kinds of structures have received a lot of research attention over recent years due to their capacity to generate easy-to-manufacture and lightweight components with enhanced mechanical properties. Despite a large amount of work available in the literature, the prediction of the mechanical behavior of lattice structures is still an open issue for researchers. Numerical simulations can help to better understand the mechanical behavior of such a kind of structure without undergoing long and expensive experimental campaigns. In this work, we compare numerical and experimental results of a uniaxial tensile test for stainless steel 316L octet-truss lattice specimen. Numerical simulations are based on both the nominal as-designed geometry and the as-build geometry obtained through the analysis of µ-CT images. We find that the use of the as-build geometry is fundamental for an accurate prediction of the mechanical behavior of lattice structures.

scholarly journals Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Joint Strength ◽  
Solid Phase ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Processes

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.

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