THE EFFECT OF LOW MELTING POINT IMPURITIES ON THE PROPERTIES OF Al-Li ALLOYS

1987 ◽  
Vol 48 (C3) ◽  
pp. C3-685-C3-691 ◽  
Author(s):  
D. WEBSTER
Keyword(s):  
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.


Author(s):  
William Krakow

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.


2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-99-Pr7-102 ◽  
Author(s):  
G. Dosseh ◽  
D. Morineau ◽  
C. Alba-Simionesco
Keyword(s):  

1987 ◽  
Vol 48 (C1) ◽  
pp. C1-495-C1-501 ◽  
Author(s):  
Y. FURUKAWA ◽  
M. YAMAMOTO ◽  
T. KURODA

1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.


2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  


Alloy Digest ◽  
1979 ◽  
Vol 28 (12) ◽  

Abstract CERROTRU Alloy is a bismuth-base eutectic alloy that melts at 281 F (138 C). It has the highest melting point of the bismuth-base alloys commonly used in industry. It provides production engineers with an easily castable material that is ready for use soon after it freezes. The alloy can be recovered easily and recycled into new uses any number of times. Cerrotru alloy has many uses including anchoring, molds for plastics, filler for tube bending and liquid metal in heat treating. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on casting, heat treating, and machining. Filing Code: Bi-15. Producer or source: Cerro Metal Products.


Alloy Digest ◽  
1970 ◽  
Vol 19 (12) ◽  

Abstract CRM MOLYBDENUM-50 RHENIUM is a high-melting-point alloy for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Mo-11. Producer or source: Chase Brass & Copper Company Inc..


Alloy Digest ◽  
1970 ◽  
Vol 19 (8) ◽  

Abstract CRM RHENIUM is a commercially pure, high-melting-point metal for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Re-1. Producer or source: Chase Brass & Copper Company Inc..


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