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Search Results: 1 - 10 of 8111 matches for " AM50 magnesium alloy "
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Low Porosity in Cast Magnesium Welds by Advanced Laser Twin-Spot Welding  [PDF]
Karl Fahlstr?m, Jon Blackburn, Leif Karlsson, Lars-Erik Svensson
Materials Sciences and Applications (MSA) , 2019, DOI: 10.4236/msa.2019.101006
Abstract: Porosity is reported to be a major issue when welding cast magnesium. Therefore, it is important to understand the pore formation mechanisms and find procedures that could be used to reduce porosity. This study investigated the possibility of using twin-spot optics for reducing the porosity in laser welded cast magnesium. Two twin-spot welding setups were compared using either a beam splitter or twin-spot welding with primary and secondary (placed in front of the primary optic) optics. The results showed that welding with a dual optic setup with a defocused secondary beam reduced the volumetric porosity in the weld to 5%. The highest levels of volumetric porosity were 30%, and were a result of using the dual optic setup, but with a defocused primary beam. No clear relation between the level of porosity and power or welding speed was found. It was found that the amount of porosity depended on the balance of the energy input (controlled by defocusing) between the two beams. Porosity formation can be reduced if the energy from the first beam results in the nucleation and initial growth of pores. Reheating by the second beam then allows the pores to grow and escape from the molten material without melting additional base material. Furthermore, twin-spot welding is shown to be a promising combination of a production friendly solution and high quality welding.
Microstructural Analysis of AM50/Mg2Si Cast Magnesium Composites
M.A. Malik,K. Majchrzak,K.N. Braszczyńska-Malik
Archives of Foundry Engineering , 2012,
Abstract: AM50/Mg2Si composites containing 5.7 wt. % and 9.9 wt. %. of Mg2Si reinforcing phase were prepared successfully by casting method.The microstructure of the cast AM50/Mg2Si magnesium matrix composites was investigated by light microscopy and X-ray diffractometry (XRD). The microstructure of these composites was characterized by the presence of α-phase (a solid solution of aluminium in magnesium), Mg17Al12 (γ-phase), Al8Mn5 and Mg2Si. It was demonstrated that the Mg2Si phase was formed mainly as primary dendrites and eutectic.
Heat Transfer between Casting and Die during High Pressure Die Casting Process of AM50 Alloy-Modeling and Experimental Results

Zhipeng GUO,Shoumei XIONG,Sang-Hyun Cho,Jeong-Kil Choi,

材料科学技术学报 , 2008,
Abstract: A method based on die casting experiments and mathematic modeling is presented for the determination of the heat flow density (HFD) and interfacial heat transfer coefficient (IHTC) during the high pressure die casting (HPDC) process. Experiments were carried out using step shape casting and a commercial magnesium alloy, AM50. Temperature profiles were measured and recorded using thermocouples embedded inside the die.Based on these temperature readings, the HFD and IHTC were successfully determined and the calculation results show that the HFD and IHTC at the metal-die interface increases sharply right after the fast phase injection process until approaching their maximum values, after which their values decrease to a much lower level until the dies are opened. Different patterns of heat transler behavior were found between the die and the castingat different thicknesses. The thinner the casting was, the more quickly the HFD and IHTC reached their steady states. Also, the values for both the HFD and IHTC values were different between die and casting at different thicknesses.
Microstructure of high-pressure die-casting AM50 magnesium alloy
K.N. Braszczynska -Malik,R. Dabrowski,J. Braszczynski
Archives of Foundry Engineering , 2009,
Abstract: Microstructure analyses of high-pressure die-casting AM50 magnesium alloy are presented. Investigated pressure casting wasproduced on a cold chamber die-casting machine with locking force at 1100 tones in “FINNVEDEN Metal Structures”. Light microscopyand X-ray phase analysis techniques were used to characterize the obtained material. In microstructure, an
Microstructure of AM50 die casting magnesium alloy
A. Kie?bus,T. Rzychoń,R. Cibis
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: AM50 magnesium alloy allows high-energy absorption and elongation at high strength and has goodcastability. It contains aluminum and manganese. Typically, it is used in automotive industry for steering wheels,dashboards and seat frames. The aim of this paper is to present the results of investigations on the microstructureof the AM50 magnesium alloy in an ingot condition and after hot chamber die casting.Design/methodology/approach: Die casting was carried out on 280 tone locking force hot-chamber die castingmachine. For the microstructure observation, a Olympus GX+70 metallographic microscope and a HITACHIS-3400N scanning electron microscope with a Thermo Noran EDS spectrometer equipped with SYSTEM SIXwere used.Findings: Based on the investigation carried out it was found that the AM50 magnesium alloy in as ingotcondition is characterized by a solid solution structure a with partially divorced eutectic (a + Mg17Al12) andprecipitates of Mn5Al8 phase. After hot chamber die casting is characterized by a solid solution structure awith fully divorced eutectic a + Mg17Al12. Moreover, the occurrence of Mn5Al8 phase and some shrinkageporosity has been proved.Research limitations/implications: Future researches should contain investigations of the influence of the diecasting process parameters on the microstructure and mechanical properties of AM50 magnesium.Practical implications: AM50 magnesium alloy can be cast with cold- and hot-chamber die casting machine.Results of investigation may be useful for preparing die casting technology of this alloy.Originality/value: The results of the researches make up a basis for the investigations of new magnesium alloysfor hot chamber die casting with addition of RE elements designed to exploitation in temperature to 175°C.
RELATIONSHIP BETWEEN METAL-DIE INTERFACIAL HEAT TRANSFER COEFFICIENT AND CASTING SOLIDIFICATION RATE IN HIGH PRESSURE DIE CASTING PROCESS
压铸过程中铸件-铸型界面换热系数与铸件凝固速率的关系

GUO Zhipeng,XIONG Shoumei,Mei Li,John Allison,
郭志鹏
,熊守美,Mei Li,John Allison

金属学报 , 2009,
Abstract: Based on die casting experiments, metal--die interfacial heat transfer coefficient (IHTC or h) was determined, and it is found that the IHTC changes linearly with the solidification rate v, i.e., h=kh-vv+ω, where kh-v is a function of the initial die surface temperature and the casting thickness while ω is a constant. Both kh-v and ω can be calculated by applying the regression method. Such relationship between h and v is suitable for both AM50 magnesium alloy and ADC12 aluminum alloy.
Thermal characteristics of the AM50 magnesium alloy
W. Kasprzak,J.H. Sokolowski,M. Sahoo,L.A. Dobrzański
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The goal of this publication is to demonstrate the laboratory metal casting simulation methodology based on controlled melting and solidification experiments. The thermal characteristics of the AM50 magnesium alloy during melting and solidification cycles were determined and correlated with the test samples’ microstructural parameters.Design/methodology/approach: A novel methodology allowed to perform variable solidification rates for stationary test samples. The experiments were performed using computer controlled induction heating and cooling sources using Ar for melt protection and test sample cooling.Findings: Thermal analysis data indicated that the alloy’s melting range was between approximately 434 and 640°C. Increasing the cooling rate from 1 to 4°C/s during solidification process reduced the Secondary Dendrite Arm Spacing from approximately 64 to 43μm. The temperatures of the metallurgical reactions were shifted toward the higher values for faster solidification rates. Fraction liquid curve indicates that at the end of melting of the α(Mg)-β(Mg17Al12) eutectic, i.e., 454.2°C the alloy had a 2% liquid phase.Research limitations/implications: Future research is intended to address the development of a physical simulation methodology representing very high solidification rates used by High Pressure Die Casting (HPDC) and to assess the microstructure refinement as a function of solidification rates.Practical implications: Advanced simulation capabilities including non-equilibrium thermal and structural characteristics of the magnesium alloys are required for the development of advanced metal casting technologies like vacuum assisted HPDC and its heat treatment.Originality/value: The presented results point out the direction for future research needed to simulate the alloy solidification in a laboratory environment representing industrial casting processes.
Influence of Nd on the mechanical properties and high temperature creep properties of AM50 magnesium alloy
Nd对AM50力学性能及高温性能的影响

HUANG Xiaofeng FU Penghuai LU Chen DING Wenjiang,
黄晓锋
,付彭怀,卢晨,丁文江

材料研究学报 , 2004,
Abstract: 对加Nd的AM50镁合金铸态试样进行固溶处理(420℃/12 h),研究了Nd对其显微组织、力学性能和抗高温蠕变性能的影响.结果表明:Nd的加入细化了晶粒,导致AM50合金室温力学性能的提高.Nd在AM50合金中形成了Al11Nd3高温稳定相,Al11Nd3的存在使加Nd的AM50合金在200℃的稳态蠕变率及高温(150℃)力学性能大幅度提高.
Influence of Si on the mechanical properties and high temperature creep properties of AM50 magnesium alloy
Si对AM50力学性能和高温蠕变性能的影响

HUANG Xiaofeng WANG Qudong LU Chen DING Wenjiang,
黄晓锋
,王渠东,卢晨,丁文江

材料研究学报 , 2004,
Abstract: 在基体合金AM50中分别加入Si和Ca,研究了Si和Ca对AM50-xSi合金的微观组织、力学性能及蠕变性能的影响.结果表明:加入Si后,合金高温蠕变性能随Si量的增加而增加并超过了AS41的水平;在AM50-xSi中加入微量Ca以后,合金中的Mg2Si相得到细化,从汉字状转变成颗粒状,室温及150℃拉伸性能明显提高.
Thermal and structural characteristics of the AM50 magnesium alloy
W. Kasprzak,J.H. Sokolowski,M. Sahoo,L.A. Dobrzański
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The goal of this publication is to demonstrate the laboratory metal casting simulation methodology based on controlled melting and solidification experiments. The thermal characteristics of the AM50 magnesium alloy during melting and solidification cycles were determined and correlated with the test samples’ microstructural parameters.Design/methodology/approach: A novel methodology allowed to perform variable solidification rates for stationary test samples. The experiments were performed using computer controlled induction heating and cooling sources using Argon for melt protection and test sample cooling.Findings: Thermal analysis data indicated that the alloy’s melting range was between approximately 434 and 640°C. Increasing the cooling rate from 1 to 4°C/s during solidification process reduced the Secondary Dendrite Arm Spacing from approximately 64 to 43μm. The temperatures of the metallurgical reactions were shifted toward the higher values for faster solidification rates. Fraction liquid curve indicates that at the end of melting of the α(Mg)-β(Mg17Al12) eutectic, i.e., 454.2oC the alloy had a 2% liquid phase.Research limitations/implications: Future research is intended to address the development of a physical simulation methodology representing very high solidification rates used by High Pressure Die Casting (HPDC) and to assess the microstructure refinement as a function of solidification rates.Practical implications: Advanced simulation capabilities including non-equilibrium thermal and structural characteristics of the magnesium alloys are required for the development of advanced metal casting technologies like vacuum assisted HPDC and its heat treatment.Originality/value: The presented results point out the direction for future research needed to simulate the alloy solidification in a laboratory environment representing industrial casting processes.
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