Enhanced Mechanical Properties of A206 Aluminum Casting Alloy by Addition of Rare Earth Elements

2005 ◽  
Vol 475-479 ◽  
pp. 441-444 ◽  
Author(s):  
Joong Hwan Jun ◽  
Jeong Min Kim ◽  
Ki Duk Seong ◽  
Ki Tae Kim ◽  
Woon Jae Jung

Changes in tensile properties of A206 Al-Cu-Mg casting alloys containing trace amount of rare earth(RE) elements up to 0.2% were investigated and discussed in relation to the microstructural evolution. The A206 alloy with 0.1%RE shows higher values of ultimate tensile strength(UTS) and yield strength(YS) than A206 alloy at room and elevated temperatures up to 300oC, whereas no remarkable change is found in elongation with respect to RE addition. In view of X-ray diffractometry(XRD) and transmission electron microscopy(TEM), the improvement of tensile strength in the A206 alloy with 0.1%RE would be caused by higher number density of Al2Cu(q¢) strengthening precipitates.

2006 ◽  
Vol 510-511 ◽  
pp. 214-217 ◽  
Author(s):  
Joong Hwan Jun ◽  
Bong Koo Park ◽  
Jeong Min Kim ◽  
Ki Tae Kim ◽  
Woon Jae Jung

Influences of Ca addition on microstructures and mechanical properties at room and elevated temperatures up to 300oC were investigated for ZE41 (Mg-4%Zn-1%Zn)-(0~1.0)%Ca permanent mould casting alloys, based on the results from X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and tensile tests. The microstructure of ZE41 alloy is characterized by dendritic α-(Mg) grains surrounded by Mg7Zn3-based eutectic network phase. The average size of α grains decreases continuously with an increase in Ca content. The Ca-containing ZE41 alloys have Mg7Zn3-(RE)-(Ca) eutectic phase, in which Ca is distributed inhomogeneously owing to its strong segregation power. It is noteworthy that tensile yield strength (YS) for the ZE41 alloy was enhanced with increasing Ca content at all temperatures up to 300oC, which demonstrates that Ca can play a beneficial role in improving its tensile strength at room and elevated temperatures. The ZE41 alloy with 0.5%Ca showed the highest ultimate tensile strength (UTS) at room temperature, but in the range of 175 to 300oC, the higher the Ca content, the greater the UTS. The improved tensile strength of the Ca-containing ZE41 alloy would be caused by the refined α grains and higher thermal stability of the Mg7Zn3-(RE)-(Ca) eutectic phase.


2007 ◽  
Vol 26-28 ◽  
pp. 137-140 ◽  
Author(s):  
Joong Hwan Jun ◽  
Bong Koo Park ◽  
Jeong Min Kim ◽  
Ki Tae Kim

Influences of Gd or Y addition on microstructures and tensile properties at room and elevated temperatures were investigated for T6-treated Mg-3%Nd-0.5%Zn-0.4%Zr casting alloys, on the basis of experimental results from X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, tensile and creep tests. Microstructures of the T6-treated alloys are characterized by recrystallized α-(Mg) grains containing various nano-sized precipitates such as Mg41Nd5, Zn2Zr3 and Zr particles. In T6 condition, most of added Gd and Y elements are dissolved in Mg41Nd5 precipitates rather than formation of new phases. Tensile properties and creep resistance of the Mg-3%Nd-0.5%Zn-0.4%Zr alloy are remarkably increased by the addition of Gd or Y, but their efficiencies are substantially the same.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
N. M. P. Low ◽  
L. E. Brosselard

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.


Author(s):  
G. M. Micha ◽  
L. Zhang

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.


Alloy Digest ◽  
1974 ◽  
Vol 23 (12) ◽  

Abstract FEDERATED F401.5Ni is a heat-treatable aluminum casting alloy with high strength and good wear resistance in the fully heat-treated condition. It is recommended for castings requiring good strength at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-212. Producer or source: Federated Metals Corporation, ASARCO Inc..


Alloy Digest ◽  
1979 ◽  
Vol 28 (1) ◽  

Abstract ELEKTRON QH21A is a magnesium-base casting alloy developed to meet the ever increasing requirements for casting alloys to operate at elevated temperatures. It is of particular interest to designers and stress engineers for highly stressed components operating at temperatures up to 480 F (250 C), especially where pressure tightness is a requirement. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: Mg-72. Producer or source: Magnesium Elektron Inc..


Author(s):  
M. G. Mahmoud ◽  
Y. Zedan ◽  
A. M. Samuel ◽  
V. Songmene ◽  
F. H. Samuel

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402110077
Author(s):  
Chao Du ◽  
Cuirong Liu ◽  
Xu Yin ◽  
Haocheng Zhao

Herein, we synthesized a new polyethylene glycol (PEG)-based solid polymer electrolyte containing a rare earth oxide, CeO2, using mechanical metallurgy to prepare an encapsulation bonding material for MEMS. The effects of CeO2 content (0–15 wt.%) on the anodic bonding properties of the composites were investigated. Samples were analyzed and characterized by alternating current impedance spectroscopy, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, tensile strength tests, and anodic bonding experiments. CeO2 reduced the crystallinity of the material, promoted ion migration, increased the conductivity, increased the peak current of the bonding process, and increased the tensile strength. The maximum bonding efficiency and optimal bonding layer were obtained at 8 wt% CeO2. This study expands the applications of solid polymer electrolytes as encapsulation bonding materials.


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