Effect of Stirring on the Quality of ADC 12 Cast Aluminium Alloy

2020 ◽  
Vol 867 ◽  
pp. 98-102
Author(s):  
H.C. Kis Agustin ◽  
Indra Sidharta ◽  
Leonard

Stirring is one the most utilized process in small foundry. It is used for homogenizing the temperature and mixing process during melting. However, stirring may cause undesirable effect to the quality of castings if it is not managed properly. Bifilm is one of the defects that can be detrimental to the quality of aluminium castings, and its formation can be related to the stirring during melting. The research aim is to investigate the effect of stirring during melting of cast aluminium alloys. The quality of castings is approached by the term of bifilm index and mechanical properties. ADC 12 cast aluminium alloys is used in the experiment. The ADC 12 ingots are melted at 720 °C, and then stirred for 0, 3 and 5 minutes. Reduced Pressure Test is used for determining the bifilm index. Samples for mechanical testing are also casted into specific geometry. Results indicate that prolonged stirring time increases the bifilm index, indicating that more porosity and bifilm oxide are formed. Extended stirring time instigates more turbulence in liquid metal, hence surface oxides are folded and trapped in the bulk liquid metal. Charpy impact test, hardness test and tensile test have also carried out. More Porosity and bifilm oxide are formed in the samples and tend to decrease the mechanical property.

2015 ◽  
Vol 647 ◽  
pp. 188-194
Author(s):  
Břetislav Skrbek

The porosity is unwanted phenomenon mostly that is tried to eliminate. The pores are initiation site of fatigue fractions usually, they worse strength and ductility of materials, quality of machined surfaces and their following surface treatment.


2016 ◽  
Vol 851 ◽  
pp. 168-172
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Tegar Rileh Argihono ◽  
Ryan Sutrisno

Mechanical and microstructure of double side weld with various angle groove was studied in this research. LR Gr A steel plates (12 mm thickness) were welded using GMAW with corresponding 180 A, 23 V, and 20 l/min respectively with current, voltage, and gas flow. Shielding gas and filler metals used are argon and ER 70S-6. The angle groove that used were 20⁰, 40⁰ and 60⁰. The measured of mechanical properties with regard to hardness, toughness and strength using, Vickers hardness test, Charpy impact test and tensile test respectively The microstructure examined with optical microscope. The results show that the highest hardness values found in welds with groove angle 40ͦ. The transition temperatures of weld metals are at temperatures between -20°C to 0°C. Weld metals with all variations of the groove angle has a value of less than 0.1 mmpy. Microstructure of base metals and HAZ were ferrite and pearlite. While the microstructure of weld metals are accicular ferrite, grain boundary ferrite and Widmanstatten ferrite.


2019 ◽  
Vol 943 ◽  
pp. 26-33
Author(s):  
Xia Zhu ◽  
Keiji Ogi ◽  
Nagatoshi Okabe

The hardness test, Charpy impact test, and axial expansion experiment were performed on a medium carbon steel S35C specimen typically used for shaft materials after first subjecting it to quenching and tempering heat treatment under different heating temperatures/time conditions. The effect of the tempering conditions on the mechanical properties of the specimen and the limit of the diameter-enlarged ratio used for evaluating the workability of the partial diameter-enlarged were investigated. The summary of the results are as follows: after quenching at 880 °C, a fine troostite or sorbite structure was obtained under all heat treatment conditions at heating temperatures of 550 °C to 675 °C, and heating times of 0.5 h to 1.5 h. An improvement was shown in the limit of the diameter-enlarged ratio because the quenching and tempering heat treatment led to an increase in the Charpy impact value/ductility as well as a reduction in the hardness, tensile strength, and yield strength; the partial diameter-enlarged process could be performed on the heat treated material at almost the same deformation speed as a cold-drawn material with a much lower axial pressure; it was possible to estimate the diameter-enlarged deformation behavior using the tempering parameter M. We confirmed that the quenching tempering heat treatment performed in this study facilitates the improvement of the workability of the diameter-enlarged.


2011 ◽  
Vol 704-705 ◽  
pp. 1035-1040
Author(s):  
Da Yong You

The Charpy impact test、hardness test、microstructure and morphology analysis of impact fracture by SEM were introduced to research the difference of impact toughness on 25Mn, which were in the station of hot-rolled、normalized and quenched & tempered. The resulted showed that the changes of load、deformation and energy exhaust in difference stage of deformation and fracture could be gained by Charpy impact test. 25Mn in quenched & tempered has more deformation resistance and deformation property than which in other stations. The total impact values was 6J higher than which in normalized in average, however, the crack propagation values was 16.78J higher in average. Ductile-brittle property of the material can be estimated by the analysis of crack formation values、crack propagation values and fracture morphology on samples.


2011 ◽  
Vol 183 ◽  
pp. 37-42 ◽  
Author(s):  
Janusz Cwiek ◽  
Jerzy Łabanowski ◽  
Santina Topolska ◽  
Maria Sozańska

The paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis; microstructure examinations with the use of light microscope, scanning electron microscope (SEM); mechanical properties examinations using the Charpy impact test, and Vickers hardness test; fracture mode evaluation with SEM.


Author(s):  
Mohd Azmeer Asry ◽  
◽  
Mohd Azhar Harimon ◽  

Aluminium alloys are commonly utilised to reduce the weight of vehicles as structural components due to their good mechanical properties, lightweight characteristics, ease of fabrication, and high specific strength. During an accident, aluminium alloys are subjected to high velocity and varying loads. As a result, it is crucial to understand the impact properties of aluminium alloys. The side groove influence on the shear lip development of the aluminium alloy Al6061 was investigated in this study. The Charpy impact test under different side groove depth ratio was conducted through simulation using Abaqus. It was found that the shear lips ratio decreased when the side groove depth ratio increased. The energy absorption and force required to fracture the specimen decreased when the side groove depth ratio increased. As a result of the lower shear lips ratio, less absorb energy, and less force of impact, increasing the side groove depth ratio will tend to lower Al6061 ductility.


2018 ◽  
Vol 919 ◽  
pp. 136-143 ◽  
Author(s):  
Vojtech Senkerik ◽  
Michal Stanek ◽  
Martin Ovsik

The aim of this paper is to investigate the behavior of the recycled polymer containing the filler. The recycled polymer under investigation is polypropylene with a glass fiber filler. During grinding of plastic waste particles are formed which have a different size, shape and surface, from larger pieces to dust particles. Several recycled mixtures were made, all from original material. Samples with different particle size of recycled material were subsequently tested by mechanical testing. Included tests were Charpy impact test and Shore hardness test. Testing was conducted at different temperatures; ambient 23 °C and increased temperatures 60 ° and 100 °C. The results show a very large effect on Charpy properties and a lesser influence on the hardness of these mixtures. Mixture of smallest dust particles indicates larges change of measured properties.


2018 ◽  
Vol 919 ◽  
pp. 144-151 ◽  
Author(s):  
Ľudmila Dulebová ◽  
Karolina Glogowska ◽  
Jaroslav Hájek ◽  
Jakub Fic

Reinforcing thermoplastic polymers with nanotubes or nanoplatelets to form nanocomposites is a way to increase the usage of polymeric materials in engineering applications by improving their mechanical properties. The contribution presents the results of research from basic processing and mechanical properties of nanocomposites. Low-Density Polyethylene (LDPE) was used as a matrix for experiments. The material LDPE was modified by Halloysite nanotubes (HNT) with a mass share of 2, 4, 6 wt% of the matrix. Nanocomposites were filled with 5 wt% Polyethylene grafted with maleic anhydride (PE-graft-MA) as a compatibilizer. The specimens were prepared by injection molding and their selected mechanical properties were tested by static tensile test, Charpy impact test and Shore hardness test.


2020 ◽  
Vol 12 (4) ◽  
pp. 531-537 ◽  
Author(s):  
Hyun-Joon Park ◽  
Byung-Wook Ahn ◽  
Jae-Ha Kim ◽  
Jong-Gun Lee ◽  
Seung-Boo Jung

AA6061-T4 composites containing SiC and B4C particles were fabricated by friction stir processing (FSP) with an SKD11 tool. The microstructures and mechanical properties of the composites were investigated with various test methods. With the inclusion of ceramic particles, refined grains in the stir zone (SZ) were observed using a scanning electron microscope (SEM) and tunneling electron microscope (TEM). Because the ceramic particles facilitated grain refinement in the SZ via the pinning effect, the SZ with the particles had a much smaller grain size than the SZ without the particles. Vickers hardness test, tensile test and Charpy impact test were conducted to evaluate the mechanical properties. Mechanical properties of the SZ with the ceramic particles were improved relative to those of the SZ without the particles. Vickers hardness (from 50 to 90 HV), tensile strength (from 117 to 253 MPa) and Charpy impact absorbed energy (from 4.2 to 5.6 J) of the SZ increased with the addition of ceramic particles.


Author(s):  
C.K. Agisparayan ◽  
K.O. Low ◽  
S.T. Lim ◽  
K.J. Wong

Background:Many studies were done to assess the mechanical characteristics of the bandage casts with regards to different specifications of materials under different parameters. Many patents have been designed on the various types of casting materials such as POP, fiberglass and polyester. A recent trend in the patent is to explore a hybrid combination for bandage casts to withstand structural failure, crack formation or deformation.Objective:This study aims to study the effect of impact force on plaster of Paris, fiberglass and hybrid bandage casts.Methods:There different bandage casts were constructed using plaster of Paris, fiberglass and a hybrid combination of plaster of Paris and fiberglass. They were subjected to Charpy impact test, three-point flexural test, and Rockwell B hardness test.Results:The impact characteristics, energy absorption properties, ductility, rigidity, strength, stiffness and indentation hardness of the hybrid bandage cast were found to be greatly influenced from being a composite of two casts and interfaces. It was found that the impact energy capable of being absorbed prior to fracture for the plaster of Paris, fiberglass and hybrid were 1.225 Joules, 11.125 Joules and 6.750 Joules, respectivelyConclusion:Hybrid bandage casts possessed improved impact characteristics compared to plaster of Paris bandage casts and more cost-effectiveness as compared to fiberglass bandage casts


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