Effect of Slope Plate Variables and Reheating on the Semi-Solid Structure of Al Alloys

2006 ◽  
Vol 116-117 ◽  
pp. 201-204 ◽  
Author(s):  
S. Ashouri ◽  
Mahmoud Nili-Ahmadabadi

Semi-solid forming (SSF) involves alloys with non-dendrite microstructure that contain spherical solid particles in the liquid matrix. This process is generally divided into three main steps: feedstock manufacturing, reheating and forming. Feedstock has the main effect on the cost and quality of product. Many researches have been carried out to reduce the cost of feedstock manufacturing. Slope plate is a simple semi-solid process that can reduce the cost of feedstock. In this study a Cu plate with water and without water circulation was used to investigate the effect of pouring temperature, cooling rate during casting and solidification in the mold on the microstructure. Cast ingots with optimized microstructure were reheated in various time and temperatures in semi-solid region to obtain kinetics of globularization and solid grain growth.

2006 ◽  
Vol 116-117 ◽  
pp. 205-208 ◽  
Author(s):  
P. Babaghorbani ◽  
S. Salarfar ◽  
Mahmoud Nili-Ahmadabadi

Reheating process in the semi-solid state is a very important step in the thixoforming process. In this research semi-solid ductile cast iron and Al alloys (Al-2.5Si, Al356) prepared by inclined plate method, were reheated to examine the effect of reheating conditions on the microstructure and coarsening kinetics of the alloys. For ductile cast iron, solid fraction at different reheating temperatures and holding times was obtained and based on these results the optimum reheating temperature range was determined. In the case of Al alloys increase of holding time in the semi-solid state, leads to increase of liquid fraction, solid grain size and improvement of sphericity of solid particles. In addition, the results show that coarsening kinetics of microstructures of both alloys during reheating was diffusion controlled and can be mostly treated by Ostwald ripening theory.


2006 ◽  
Vol 510-511 ◽  
pp. 782-785 ◽  
Author(s):  
Suk Won Kang ◽  
Ki Bae Kim ◽  
Dock Young Lee ◽  
Jung-Hwa Mun ◽  
Eui Pak Yoon

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 722 ◽  
Author(s):  
Yubo Zhang ◽  
Jiaming Liu ◽  
Ying Fu ◽  
Jinchuan Jie ◽  
Yiping Lu ◽  
...  

In the present work, Cu-Pb-Sn and Q235 laminated composite were fabricated by a horizontal semisolid rolling procedure. The interfacial structure, elemental distribution, and properties of the composite were investigated. Finite-element simulation was conducted to analyze the temperature field and solidification process during the semisolid rolling. An appropriate semi-solid region was observed at a pouring temperature of 1598 K in the simulation, which would effectively kept fluidity and avoided casting defects. The experimental results showed that good interface between Cu-Pb-Sn alloy and Q235 steel was achieved by the proposed process at 1598 K, without casting defects or excessive deformation. The Cu and Fe alloys were bonded mainly by the diffusion of Fe into Cu matrix, and a handful of microscopic Pb-rich layer. Fine Pb-rich precipitates were uniformly distributed in the Cu-Pb-Sn alloy, and were considered to be advantageous to the self-lubrication property. The average tensile-shear strength of the interface was higher than 57.68 MPa at a pouring temperature of 1598 K, which fulfilled the requirements for a further extrusion process.


2011 ◽  
Vol 264-265 ◽  
pp. 272-277 ◽  
Author(s):  
Nurşen Saklakoğlu ◽  
S. Gencalp ◽  
Şefika Kasman ◽  
İ.E. Saklakoğlu

Thixoforming and related semi-solid processing (SSP) methods require thixotropic materials. One of the many SSP techniques is the cooling slope (CS) casting process, which is simple and has minimal equipment requirements, and which is able to produce feedstock materials for semisolid processing. When the feedstock is reheated to the semisolid temperature range, non-dendritic, spheroidal solid particles in a liquid matrix suitable for thixoforming are obtained. In this study, equipment for the CS technique was first established, and then the effects of the pouring temperature and inclined slope angle on the microstructures of A380 aluminum alloy (ISOAlSi8Cu3Fe) were studied. Optimum parameters for thixoforming experiments were selected, and it was found that the microstructure produced by the inclined plate depended on its angle and the pouring temperature.


2013 ◽  
Vol 765 ◽  
pp. 112-116
Author(s):  
Franco Chiesa ◽  
David Levasseur ◽  
Jocelyn Baril

In order to compare the semi-solid SEED casting process to the Low Pressure Permanent Mould process (LPPM), the same part has been produced in aluminium A356 (AlSi7Mg04) using the two methods. The processes were first compared from an operational standpoint: pouring temperature, filling sequence, production rate and mould maintenance. In addition, the metallurgical quality of the castings was evaluated by measuring the tensile properties at 6 locations in the part; the metallographic structures were also compared. Filling and solidification modeling allowed the prediction of the filling sequence and local solidification times everywhere in the casting. The SEED process was generally found to deliver a finer structure, a near net shape casting and a much higher productivity. LPPM parts were more uniform in structural and mechanical properties as verified at 6 locations in the castings.


2019 ◽  
Vol 285 ◽  
pp. 398-402 ◽  
Author(s):  
Hong Zhang ◽  
Da Quan Li ◽  
Wen Ying Qu ◽  
Fan Zhang ◽  
Min Luo ◽  
...  

Controlling the morphology of the microstructure of the slurry is important during semi-solid die casting. For this project, semi-solid slugs were produced using the SEED (Swirled Enthalpy Equilibrium Device) process, where a fully liquid metal is poured into a steel crucible and cooled into the semi-solid temperature range, and the crucible and slurry are then swirled and cooled to the appropriate temperature (and solid fraction) for semi-solid casting. The pouring temperature of the melt into the crucible during SEED processing has been shown to influence the morphology and size of the aluminum solid particles within the slurry, which can influence the distribution and segregation of the solid particles during die casting. In this study, a specially-designed die with a serpentine-shaped flow channel has been used to study the distribution of the solid particles during semi-solid die casting. The experimental results show that a dendritic structure is formed when the liquid is poured from a high temperature, while a globular semi-solid morphology is more easily formed when poured from a low superheat. The current results also show that a dendritic structure leads to severe segregation during die casting.


Author(s):  
M.A. Egyan ◽  

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.


Author(s):  
Nur Maimun ◽  
Jihan Natassa ◽  
Wen Via Trisna ◽  
Yeye Supriatin

The accuracy in administering the diagnosis code was the important matter for medical recorder, quality of data was the most important thing for health information management of medical recorder. This study aims to know the coder competency for accuracy and precision of using ICD 10 at X Hospital in Pekanbaru. This study was a qualitative method with case study implementation from five informan. The result show that medical personnel (doctor) have never received a training about coding, doctors writing that hard and difficult to read, failure for making diagnoses code or procedures, doctor used an usual abbreviations that are not standard, theres still an officer who are not understand about the nomenclature and mastering anatomy phatology, facilities and infrastructure were supported for accuracy and precision of the existing code. The errors of coding always happen because there is a human error. The accuracy and precision in coding very influence against the cost of INA CBGs, medical and the committee did most of the work in the case of severity level III, while medical record had a role in monitoring or evaluation of coding implementation. If there are resumes that is not clearly case mix team check file needed medical record the result the diagnoses or coding for conformity. Keywords: coder competency, accuracy and precision of coding, ICD 10


Sign in / Sign up

Export Citation Format

Share Document