scholarly journals Injection Tests and Effect on Microstructure and Properties of Aluminium 7075 Direct Thermal Method Feedstock Billets

2014 ◽  
Vol 611-612 ◽  
pp. 1637-1644 ◽  
Author(s):  
Asnul Hadi Ahmad ◽  
S. Naher ◽  
Dermot Brabazon
Keyword(s):  
Liquid Phase ◽  
Secondary Phase ◽  
Solid Metal ◽  
Microstructure Analysis ◽  
Thermal Method ◽  
Processing Unit ◽  
Grain Formation ◽  
Experimental Works ◽  
Semi Solid ◽  
Selection Of

The success of semi-solid metal forming is dependent on a globular solid grain formation within a liquid phase. This paper presents experimental works concerning semi-solid metal processing of aluminium 7075 feedstock billets which were produced by direct thermal method. The flowability of feedstock billets was evaluated by an injection test processing unit. The feedstock billets were heated to a temperature of 620 °C by using a box furnace before transferred into a forming die. The formed feedstock billet was removed from the forming die after it was cooled to ambient temperature. Several analyses were conducted on the formed feedstock billets including dimensional measurement and microstructure analysis. The results show that the feedstock billets which contained highest amount of free secondary phase were most successfully formed. Microstructure analysis results also revealed the formation of more globular and larger α–Al solid grains in the same feedstock billets. In this experimental work, the feedstock billets with higher secondary (liquid) phase gives a significant effect to formability. It can be concluded that in order to get successful formability of direct thermal method feedstock billets, the billets need to have higher secondary phase content. Thus, the selection of proper feedstock billets is important to determine the success of the SSM processing.

scholarly journals Transient Liquid Phase Bonding of Semi-Solid Metal 7075 Aluminum Alloy using ZA27 Zinc Alloy Interlayer

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 637 ◽  
Author(s):  
Chaiyoot Meengam ◽  
Yongyuth Dunyakul ◽  
Dech Maunkhaw ◽  
Suppachai Chainarong
Keyword(s):  
Aluminum Alloy ◽  
Liquid Phase ◽  
Bonding Strength ◽  
Transient Liquid Phase ◽  
Solid Metal ◽  
Bonding Time ◽  
Zinc Alloy ◽  
Transient Liquid Phase Bonding ◽  
Bonding Zone ◽  
Semi Solid

Transient Liquid Phase Bonding (TLPB) process of semi-solid metal 7075 aluminum alloys (SSM7075) using 50 μm thick of ZA27 zinc alloys as interlayers for the experiment were carried out under bonding temperatures of 480 and 540 °C and bonding times of 30, 60, 90 and 120 min respectively. In the bonding zone, the semi-solid state of ZA27 zinc alloy interlayers were diffused into the SSM7075 aluminum alloy. Examination of the bonding zone using Scanning Electron Microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS) showed that the precipitation of the intermetallic compound of η(Zn–Al–Cu), β(Al2Mg3Zn3), T′(Zn10Al35Cu55) and MgZn2 were formed in the bonding zone. The better homogenized microstructure in the bonding zone was formed when increasing bonding time and bonding temperature. The highest bonding strength was recorded at 17.44 MPa and average hardness was at 87.67 HV with the bonding time of 120 min and temperature at 540 °C. Statistically, the coefficient of determination analysis of bonding strength data was at 99.1%.

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.

SSM Provides Important Advantages; So, why has SSM Failed to Achieve Greater Market Share?

2014 ◽  
Vol 217-218 ◽  
pp. 481-486 ◽  
Author(s):  
John L. Jorstad
Keyword(s):  
Turbulent Flow ◽  
Heat Treating ◽  
Solid Metal ◽  
Light Metals ◽  
Solidification Shrinkage ◽  
Air Entrapment ◽  
Thin Sections ◽  
Metal Processing ◽  
Semi Solid ◽  
Minimum Heat

Semi solid metal processing has numerous technical and economic advantages, such as viscous, non-turbulent flow (thus no air entrapment during casting), ability to fill ultra-thin sections (thus reduced part weight), little solidification shrinkage in the die (thus little or no porosity), minimum heat imparted to tooling (thus long tool life) and good response to T-5 aging (thus reduced heat treating costs). Still, SSM has never achieved a prominent position in the field of light metals casting Why? Perhaps the reason was largely the down economy of recent years and SSM will yet emerge with the prominence once expected of it.

Impact of melt treatment on semi-solid metal processing

2007 ◽  
Vol 436 (1-2) ◽  
pp. 86-90 ◽  
Author(s):  
Sahrooz Nafisi ◽  
Reza Ghomashchi
Keyword(s):  
Solid Metal ◽  
Melt Treatment ◽  
Metal Processing ◽  
Semi Solid

Typographical and Editorial Solutions as a Source of Hybridization in Polish Non-Fiction Literature

Tekstualia ◽  
2021 ◽  
Vol 3 (66) ◽  
pp. 57-72
Author(s):  
Katarzyna Frukacz
Keyword(s):  
Spatial Layout ◽  
Non Fiction ◽  
Experimental Works ◽  
Printing Paper ◽  
Cover Design ◽  
Physical Components ◽  
Selection Of

The article focuses on the selected examples of the blurring of a book’s genre status by means of specifi c editorial solutions, such as the use of a spatial layout of the text, the differentiation of fonts, the selection of printing paper, the cover design etc. This mechanism is discussed on the example of six experimental works of contemporary Polish non-fi ction literature. Books by Filip Springer and Jarosław Mikołajewski, bordering upon literary reportage, show how the use of typography enhances the formal hybridity or even amorphousness of the text. In turn, Mariusz Szczygieł and Wojciech Tochman, their documentary narratives, emphasize the mutual synergy between the physical components of the book, which undermines the standard genre classifi cation.

scholarly journals 3D Printing of Thermo-Sensitive Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1524
Author(s):  
Sadikalmahdi Abdella ◽  
Souha H. Youssef ◽  
Franklin Afinjuomo ◽  
Yunmei Song ◽  
Paris Fouladian ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Future Directions ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Printing Technique ◽  
3D Printed ◽  
Semi Solid ◽  
Selection Of

Three-dimensional (3D) printing is among the rapidly evolving technologies with applications in many sectors. The pharmaceutical industry is no exception, and the approval of the first 3D-printed tablet (Spiratam®) marked a revolution in the field. Several studies reported the fabrication of different dosage forms using a range of 3D printing techniques. Thermosensitive drugs compose a considerable segment of available medications in the market requiring strict temperature control during processing to ensure their efficacy and safety. Heating involved in some of the 3D printing technologies raises concerns regarding the feasibility of the techniques for printing thermolabile drugs. Studies reported that semi-solid extrusion (SSE) is the commonly used printing technique to fabricate thermosensitive drugs. Digital light processing (DLP), binder jetting (BJ), and stereolithography (SLA) can also be used for the fabrication of thermosensitive drugs as they do not involve heating elements. Nonetheless, degradation of some drugs by light source used in the techniques was reported. Interestingly, fused deposition modelling (FDM) coupled with filling techniques offered protection against thermal degradation. Concepts such as selection of low melting point polymers, adjustment of printing parameters, and coupling of more than one printing technique were exploited in printing thermosensitive drugs. This systematic review presents challenges, 3DP procedures, and future directions of 3D printing of thermo-sensitive formulations.

Microstructure Evaluate System of Semi-Solid Forming

2007 ◽  
Vol 546-549 ◽  
pp. 93-96 ◽  
Author(s):  
Xiao Peng Cui ◽  
Yong Bing Liu ◽  
Zhan Yi Cao ◽  
You Fa Zhang ◽  
Qian Qian Zhang
Keyword(s):  
Magnesium Alloy ◽  
The Other ◽  
Microstructure Analysis ◽  
Analysis Software ◽  
Az91d Magnesium Alloy ◽  
Alloy Microstructure ◽  
Semi Solid

The evaluating rules for semi-solid microstructure were brought up, and the analysis software was developed on MATLAB 7.0 platform in this study. Furthermore, this system can be used not only in the Thixomolding AZ91D magnesium alloy microstructure analysis, but also in the other semi-solid processing microstructure.

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