Bismuth thermal properties

Solders. In spite of the wide use and development of solders for millennia, as of the mid-1990s most principal solders are lead- or tin-based alloys to which a small amount of silver, zinc, antimony, bismuth, and indium or a combination thereof are added. The principal criterion for choosing a certain solder is its melting characteristics, ie, soHdus and Hquidus temperatures and the temperature spread or pasty range between them. Other criteria are mechanical properties such as strength and creep resistance, physical properties such as electrical and thermal conductivity, and corrosion resistance. 

The physical properties of bismuth, summarized ia Table 1, are characterized by a low melting poiat, a high density, and expansion on solidification. Thermochemical and thermodynamic data are summarized ia Table 2. The soHd metal floats on the Hquid metal as ice floating on water. GaUium and antimony are the only other metals that expand on solidification. Bismuth is the most diamagnetic of the metals, and it is a poor electrical conductor. The thermal conductivity of bismuth is lower than that of any other metal except mercury. 

Uses. Low melting solders, low melting alloys and metallurgical additives. Bismuth is a metal with some unusual properties like Ge and Ga its volume increases in solidification. It is the most diamagnetic metal, its alloys show large thermoelectric effect with the exception of Be has the lowest absorption cross-section for thermal neutrons. 

TNBAc Explosive Properties. It is about as powerful brisant an expl as TNT Sensitivity to Impact is comparable to that of TNT its Ballistic Mortar value is 98% TNT and its Thermal Stability is somewhat lower than that of TNT as shown by Heat and Vac Stab tests(Refs 17 19a) Because of the hygroscopic nature of TNBAc. it forms expl salts with the following metals aluminum, barium, bismuth, copper, iron, lead, mercury silver tin, all of which(except Al, Bi Sn) are cryst substs and all expl on shock or by heatfRef 4). Props of the more important salts are as follows ... 

These derivatives have not only provided new synthetic pathways but have shown improved thermal stability (as in the case of arsenic ylides) and a modified pattern of chemical reactivity. The donor properties of ylides 55, 24), and most of their synthetic applications 103), have been covered in other reviews and articles 3, 26) and are not duplicated here. The general organometallic chemistry of arsenic, antimony, and bismuth is the subject of the invaluable monograph by Doak and Freedman 11). The broad scope of phosphorus ylide and pentaorganophosphorane chemistry was covered in the leading multivolume series on organophosphorus chemistry edited by Kosolapoff and Maier 3, 21). Finally, the recent... 

Equation 6.20 is a rather formidable expression. From the experimentalist s standpoint, it will be beneficial to point out some simple, yet useful, criteria when toiling with thermal conductivity. First, it is noted that thermal conductivity is not an additive property. It is generally not possible to predict the thermal conductivity of an alloy or compound from the known thermal conductivities of the substituent pure elements. For example, the thermal conductivity of polycrystaUine silver and bismuth are. 

Introduction of a support (i.e. Ti02) to these systems can induce positive effects on the active phase (FeMo), as to avoid an excessive sintering of the particles during the thermal treatment and/or modification of the reduction capacity and the acid properties. The synergy of iron molybdate and the support is therefore another way for improving the catalytic performance of these solids. Such benefitial effects have been detected in bismuth-molybdenum-titania mixed oxides prepared via sol-gel, in addition these solids resulted to be amorphous materials with a unique morphology and extraordinary dispersion of the active phase [12]. These results encouraged us to extend this field to iron molybdenum oxide catalysts. 

We report on the powder metallurgical fabrication of bismuth-antimony solid solution and the thermoelectric properties of the fabricated composites. The solid solution powders were prepared by mechanical alloying (MA) aiming at large reduction of the thermal conductivity with the very fine microstructures obtained through MA process. The prepared bismuth-antimony powders (Bi-7.5at%Sb) have been sintered by hot pressing. 

Antimony (Sb) was known at the beginning of the 17th century. It is a semimetal and is a poor conductor of heat and electricity. Bismuth (Bi) is a white, crystalline, brittle semimetal with a pinkish tinge. It has high electrical and thermal resistances. Table 2.60 summarizes some physical properties of group-Vb semimetals. 

Asato E, Hoi CM, Hulsbergen FB, Klooster NTM, Reedijk J (1991) Synthesis, structure and spectroscopic properties of bismuth citrate compounds. Part II. Comparison between crystal structures of solid bismuth citrates and commercial CBS, using thermal and spectroscopic methods. Inorg Chem 30 4210 214... 

---