Effects of Bismuth on the Microstructure and Mechanical Properties of AlSi9Cu3(Fe) Die Casting Alloys

2013 ◽  
Vol 765 ◽  
pp. 59-63 ◽  
Author(s):  
Stefano Ferraro ◽  
Giulio Timelli ◽  
Alberto Fabrizi

In secondary die cast Al alloys, Bismuth is generally considered an impurity element and present as a trace element in commercial foundry alloys. In the present work, the influence of different Bi content on the microstructure and mechanical properties of a commercial die cast AlSi9Cu3(Fe) alloy is investigated. The Bi level ranges between 0.015 and 0.3 wt.%. The results show that the presence of Bi seems to not produce significant changes in the microstructure and mechanical properties. Fine Bi-rich compounds are observed in the die cast alloys and they are mainly distributed in the interdendritic regions and along grain boundaries. TEM investigations revealed a complex Bi-Bi2Mg3eutectic structure, which presents mainly rod-type and blocky morphology.

2007 ◽  
Vol 546-549 ◽  
pp. 167-170 ◽  
Author(s):  
Li Ming Peng ◽  
Peng Huai Fu ◽  
Hai Yan Jiang ◽  
Chun Quan Zhai

Compact AM50 alloy components were cast by Low Pressure Die Casting (LPDC) process. The microstructure and mechanical properties of cast components were investigated under as-cast and heat treated states. It was found that the microstructure of LPDC AM50 is composed of α-Mg and second phases - Mg17Al12 and Al8Mn5. Compared with Gravity die casting, LPDC AM50 alloy had much coarser grains and higher density, with smaller sizes and less content of second phases. The density of AM50 alloy by LPDC process was ρ=1.7836g/cm3, with increase of 0.45% based on Gravity die casting and much more increase compared with high pressure die casting. The as-cast mechanical properties by LPDC process were: σ0.2=57.8Mpa, σb=192.3Mpa, δ=8.7%. These of Gravity die casting were: σ0.2=53Mpa, σb=173.4Mpa, δ=8.1%. UTS in LPDC increased about 20MPa, with better YTS and Elongation. Compared with that of high pressure die cast AM50, the YTS of LPDC was much lower, with comparable UTS and Elongation. The mechanical properties of the heat treated AM50 alloy were still in the same level of as-cast state. AM50 alloy by LPDC process is not necessary subjected to tempering treatment.


2019 ◽  
Vol 285 ◽  
pp. 69-74 ◽  
Author(s):  
Long Fei Li ◽  
Da Quan Li ◽  
Min Luo ◽  
Yong Zhong Zhang ◽  
Yong Lin Kang ◽  
...  

Microstructures with fine globular grains and refined eutectic structures are important to enhance the mechanical properties of A356 alloys processed by semi-solid and gravity die casting. Rare earth (RE) additions have been shown to be capable of refining both the α-Al particles as well as modify the eutectic phase of alloys. In semi-solid die casting, Al7Si0.3Mg alloys with RE concentrations (0, 0.1 and 0.4 wt.%) were used to prepare semi-solid slurries using the SEED (Swirling Enthalpy Equilibrium Device) method, and subsequently semi-solid die cast. The same compositions of alloys were also applied to gravity die casting. The microstructure and mechanical properties of castings in two processes have been characterized. Compared to the grains produced in gravity die casting, globular grains with small size (260 μm) in the semi-solid die casting significantly enhance the UTS and elongation of alloys. Although the size of grains had no change with increasing RE concentrations in alloys. The Al-Si eutectics were changed to refined morphology with the 0.1 wt.% RE addition, which enhanced the ductility of alloys in two processes. When increasing the RE addition to 0.4 wt.%, the RE-rich phases precipitated at grain boundaries, which decreased the UTS and elongation of alloys.


2006 ◽  
Vol 54 (11) ◽  
pp. 3033-3041 ◽  
Author(s):  
T. Laser ◽  
M.R. Nürnberg ◽  
A. Janz ◽  
Ch. Hartig ◽  
D. Letzig ◽  
...  

2004 ◽  
Vol 842 ◽  
Author(s):  
M. W. Wittmann ◽  
I. Baker ◽  
J. A. Hanna

ABSTRACTIn an attempt to produce a two-phase alloy consisting of a L21–structured (Fe, Ni)2MnAl-based phase in either a B2 or b.c.c. matrix, seven Fe-Ni-Mn-Al alloys were cast. Transmission electron microscopy (TEM) of the as-cast alloys revealed a range of microstructures including single phase L21, a f.c.c./B2 eutectic, and alternating, coherent 10–60 nm wide ordered and disordered b.c.c. rods aligned along <100>. A description of the phases, including chemical compositions and hardnesses is presented.


Alloy Digest ◽  
1990 ◽  
Vol 39 (5) ◽  

Abstract ZA-12 is the intermediate member of the family of three ZA die-casting alloys. Its melting point, solidification range and recommended casting-temperature range are greater than those of ZA-8. (See Alloy Digest Zn-48, January 1990). Due to these factors, ZA-12 must be die cast in cold chamber die-casting machines like conventional aluminum die-casting alloys. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, machining, and surface treatment. Filing Code: Zn-49. Producer or source: Aluminum Smelting and Refining Company Inc.. See also Alloy Digest Zn-31, September 1977.


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