scholarly journals Mechanical Properties and Melt Quality Relationship of Sr-modified Al-12Si Alloy

2015 ◽  
Vol 15 (4) ◽  
pp. 134-140 ◽  
Author(s):  
M. Uludağa ◽  
M. Uyaner ◽  
F. Yilmaz ◽  
D. Dişpinar
Keyword(s):  
Mechanical Properties ◽  
Oxide Film ◽  
Tensile Testing ◽  
Porosity Formation ◽  
Reduced Pressure ◽  
Cast Part ◽  
Pressure Test ◽  
Relationship Of ◽  
Good Agreement

Abstract The formation of oxide film on the surface of aluminium melts, i.e. bifilms, are known to be detrimental when they are incorporated into the cast part. These defects causes premature fractures under stress, or aid porosity formation. In this work, Al-12 Si alloy was used to cast a step mould under two conditions: as-received and degassed. In addition, 10 ppi filters were used in the mould in order to prevent bifilm intrusion into the cast part. Reduced pressure test samples were collected for bifilm index measurements. Samples were machined into standard bars for tensile testing. It was found that there was a good agreement with the bifilm index and mechanical properties.

Effect of Melt Quality and Quenching Temperature on the Mechanical Properties of SIMA 2024 and 7075

2012 ◽  
Vol 445 ◽  
pp. 171-176
Author(s):  
Engin Tan ◽  
Ali Riza Tarakcilar ◽  
Derya Dispinar
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
Grain Structure ◽  
Quenching Temperature ◽  
Reduced Pressure ◽  
Pressure Test ◽  
Sima Process ◽  
Spherical Grains

Spherical grains can be obtained by several semisolid processes in aluminium alloys. One of these methods is called Strain Induced Melt Activated (SIMA). In this work, commercially available 2024 and 7075 alloys were subjected SIMA process. First, optimised process parameters were investigated for the homogeneous spherical grain structure. This was followed by solution heat treatment of the parts. For the quenching medium, room temperature and 80°C boiling water was selected. The effect of different quenching temperatures over the mechanical properties was tested. Hardness, tensile and fatigue tests were applied. In addition, reduced pressure test was used to assess alloy quality and the results were compared with the mechanical tests.

scholarly journals A Review Study on the Main Sources of Porosity in Al-Si Cast Alloys

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Agnes Samuel ◽  
Yasser Zedan ◽  
Herbert Doty ◽  
Victor Songmene ◽  
Fawzy. H. Samuel
Keyword(s):  
Fatigue Testing ◽  
Point Of View ◽  
Porosity Formation ◽  
Reduced Pressure ◽  
Nucleation Sites ◽  
Pressure Test ◽  
Cast Alloys ◽  
Review Study ◽  
Pure Metals ◽  
Shrinkage Cavities

The present study was performed on A356 and B319 alloys in mechanically stirred or degassed condition. Melts were Sr-modified and grain-refined. Hydrogen content was varied from less than 0.1 ml/100 g Al to ∼0.4 ml/100 g Al; Fe was increased to 0.8% in B319 alloy. Lanthanum and cerium were added as 99.5% pure metals. Two main techniques were used to investigate porosity formation: fracture surface of tensile or fatigue test bars, or reduced pressure test (RPT) method. Porosity type and shape were examined. The results show that pore size is more influential than small scattered ones from a mechanical point of view. Tensile testing is affected by porosity located at the center of the testing bar, whereas edge porosity is responsible for crack initiation in case of fatigue testing. Intermetallics precipitate in the form of intercepted platelets which restricts the flow of the molten metal, leading to formation of shrinkage cavities. Precipitation of clusters of compounds from the liquid state such as Al2Si2Sr, Mg2Sn, Al3Ti, or added Al2O3particles would as well act as nucleation sites for porosity formation. Most oxides were observed in the form of long branched strings. In some cases, bifilms were also reported in addition to SrO and MgO.

scholarly journals A Generalized Approach for Evaluating the Mechanical Properties of Polymer Nanocomposites Reinforced with Spherical Fillers

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 830
Author(s):  
Julio Cesar Martinez-Garcia ◽  
Alexandre Serraïma-Ferrer ◽  
Aitor Lopeandía-Fernández ◽  
Marco Lattuada ◽  
Janak Sapkota ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymeric Nanocomposites ◽  
Mechanical Reinforcement ◽  
Future Studies ◽  
Three Phase ◽  
Theoretical Predictions ◽  
Filler Network ◽  
New Research ◽  
Good Agreement ◽  
Research Avenue

In this work, the effective mechanical reinforcement of polymeric nanocomposites containing spherical particle fillers is predicted based on a generalized analytical three-phase-series-parallel model, considering the concepts of percolation and the interfacial glassy region. While the concept of percolation is solely taken as a contribution of the filler-network, we herein show that the glassy interphase between filler and matrix, which is often in the nanometers range, is also to be considered while interpreting enhanced mechanical properties of particulate filled polymeric nanocomposites. To demonstrate the relevance of the proposed generalized equation, we have fitted several experimental results which show a good agreement with theoretical predictions. Thus, the approach presented here can be valuable to elucidate new possible conceptual routes for the creation of new materials with fundamental technological applications and can open a new research avenue for future studies.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.

scholarly journals Effects of Microwave Treatment in Immersed Conditions on the Mechanical Properties of Jute Yarn

Fibers ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 40
Author(s):  
Felicia Syrén ◽  
Joel Peterson ◽  
Nawar Kadi
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Glass Fibers ◽  
Microwave Treatment ◽  
Environmental Benefits ◽  
Treatment Result ◽  
Bast Fiber ◽  
Fiber Properties ◽  
Yarn Thickness ◽  
Jute Yarn

The versatile bast fiber jute has environmental benefits compared to glass fibers. However, for jute to be used in a composite, the fiber properties need to be altered. This study aims to improve the mechanical properties of jute yarn to make it more suitable for technical applications as a composite. To alter its mechanical properties, jute yarn was immersed in water during microwave treatment. The time and power of the microwave settings differed between runs. Two states of the yarn were tested: fastened and un-fastened. Tensile testing was used at the yarn and fiber level, followed by Fourier-transform infrared spectroscopy (FTIR) and microscopy. The treatment result demonstrated the ability to increase the elongation of the jute yarn by 70%. The tenacity was also increased by 34% in the fastened state and 20% in the un-fastened state. FTIR showed that no change in the molecular structure occurred. The treatments resulted in a change of yarn thickness depending on the state of the yarn. The results indicate that microwave treatment can be used to make jute more suitable for technical applications depending on the microwave treatment parameters.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

Mechanical properties of low-density paper

2020 ◽  
Vol 35 (1) ◽  
pp. 61-70
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Lili Melani ◽  
Hyoung Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Structural Change ◽  
Tensile Testing ◽  
Tensile Modulus ◽  
Gauge Length ◽  
Efficiency Factor ◽  
Low Density ◽  
Tensile Stiffness ◽  
Lower Tensile Strength

AbstractFor the mechanical properties of paper, tensile testing has been widely used. Among the tensile properties, the tensile stiffness has been used to determine the softness of low-density paper. The lower tensile stiffness, the greater softness of paper. Because the elastic region may not be clearly defined in a load-elongation curve, it is suggested to use the tensile modulus which is defined as the slope between the two points in the curve. The two points which provide the best correlation with subjective softness evaluation should be selected. Low-density paper has a much lower tensile strength, but much larger elongation at the break. It undergoes a continuous structural change during mechanical testing. The degree of the structural change should depend on tensile conditions such as the sample size, the gauge length, and the rate of elongation. For low-density paper, the tensile modulus and the tensile strength should be independent of each other. The structure efficiency factor (SEF) is defined as a ratio of the tensile strength to the tensile modulus and it may be used a guideline in developing superior low-density paper products.

Mechanical Properties of Thixoformed 7075 Feedstock Produced via the Direct Thermal Method

2015 ◽  
Vol 651-653 ◽  
pp. 1569-1574 ◽  
Author(s):  
Asnul Hadi Ahmad ◽  
Sumsun Naher ◽  
Dermot Brabazon
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Solid State ◽  
Tensile Testing ◽  
Thermal Method ◽  
Test Unit ◽  
Pouring Temperature ◽  
Injection Test ◽  
Semi Solid ◽  
Conventionally Cast

Abstracts: This paper presents an overview of measured mechanical properties of thixoformed aluminium 7075 feedstock produced by the direct thermal method (DTM). The DTM feedstock billets were processed with a pouring temperature of 685 °C and holding periods of 20 s, 40 s and 60 s before being quenched and subsequently thixoformed. A conventionally cast feedstock billet was produced with a pouring temperature of 685 °C and was allowed to solidify without quenching. The feedstock billets were later formed by an injection test unit in the semi-solid state. Tensile testing was then conducted on the thixoformed feedstock billets. Tensile properties for 7075 DTM thixoformed feedstock billets were found significantly influenced by the thixoformed component density. Samples with longer holding times were found to have higher density and higher tensile strength.

Relationship of Microstructure and Mechanical Properties in Er-Containing Aluminum Alloy

2015 ◽  
Vol 1120-1121 ◽  
pp. 1109-1114
Author(s):  
Xin Lei ◽  
Hui Huang ◽  
S.P. Wen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Treatment Process ◽  
Mg Alloys ◽  
The Other ◽  
Heat Treatment Process ◽  
Comprehensive Performance ◽  
Relationship Of ◽  
Al Mg Alloys

This study investigated the mechanical properties and microstructures of Er-containing Al–Mg alloys. The research found that the H114-T sheet of Er-containing Al–Mg alloys showed a relative good comprehensive performance in mechanical properties. With the special rolling and heat treatment process, this H114-T sheet showed different morphology of microstructures with the other sheets in Er-containing Al–Mg alloys. Grains in H114-T sheet performed irregular shape polygon, a number of subgrains appeared in grains, the amount of dislocations in grains decreased. H114-T sheet possessed a lot of Copper texture, this may be one of important factors influenced the mechanical properties.

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