Metallurgy physical

Herring C 1949 Surface tension as a motivation for sintering The Physics of Powder Metallurgy ed W E Kingston (New York McGraw-Hiii) pp 143-79... 

Physical Properties. An overview of the metallurgy (qv) and soUd-state physics of the rare earths is available (6). The rare earths form aUoys with most metals. They can be present interstitiaUy, in soUd solutions, or as intermetaUic compounds in a second phase. Alloying with other elements can make the rare earths either pyrophoric or corrosion resistant. It is extremely important, when determining physical constants, that the materials are very pure and weU characteri2ed. AU impurity levels in the sample should be known. Some properties of the lanthanides are Usted in Table 3. 

The scientific basis of extractive metallurgy is inorganic physical chemistry, mainly chemical thermodynamics and kinetics (see Thermodynamic properties). Metallurgical engineering reties on basic chemical engineering science, material and energy balances, and heat and mass transport. Metallurgical systems, however, are often complex. Scale-up from the bench to the commercial plant is more difficult than for other chemical processes. 

The essential operations of an extractive metallurgy flow sheet are the decomposition of a metallic compound to yield the metal followed by the physical separation of the reduced metal from the residue. This is usually achieved by a simple reduction or by controlled oxidation of the nonmetal and simultaneous reduction of the metal. This may be accompHshed by the matte smelting and converting processes. 

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). 

K. C. Russell and D. F. Smith, Physical Metallurgy of Controlled Expansion Invar-Type Alloys, TMS PubHcation, Warrendale, Pa., 1990. 

E. Savitsky and co-workers. Physical Metallurgy of Platinum Metals MIR Publishers, Moscow, CIS, 1978. 

J. Hatch, ed., A.luminum Properties and Physical Metallurgy, American Society for Metals, Metals Park, Ohio, 1984. 

W. C. Leshe, The Physical Metallurgy of Steels, McGraw-Hill Book Co., Inc., New York, 1981. 

Above 40 wt % hydrogen content at room temperature, zirconium hydride is brittle, ie, has no tensile ductiHty, and it becomes more friable with increasing hydrogen content. This behavior and the reversibiHty of the hydride reaction are utilized ki preparing zirconium alloy powders for powder metallurgy purposes by the hydride—dehydride process. The mechanical and physical properties of zirconium hydride, and thek variation with hydrogen content of the hydride, are reviewed in Reference 127. 

W. B. Pearson, Handbook oJEattice Spacings and Structures of Metals and Alloys, International Series on MetalPhysics and Physical Metallurgy, Pergamon Press, New York, 1958, p. 130. 

Figure 8.1 Effect of pH on corrosion of 1100-H14 alloy (aluminum) by various chemical solutions. Observe the minimal corrosion in the pH range of 4-9. The low corrosion rates in acetic acid, nitric acid, and ammonium hydroxide demonstrate that the nature of the individual ions in solution is more important than the degree of acidity or alkalinity. (Courtesy of Alcoa Laboratories from Aluminum Properties and Physical Metallurgy, ed. John E. Hatch, American Society for Metals, Metals Park, Ohio, 1984, Figure 19, page 295.)...

F.D. Richai dson. Physical Chemistry of Melts in Metallurgy, vols I II. Academic Piess, London (1974). 

N. Sano, W.-K. Lu, and P. V. Riboud (eds). Advanced Physical Chemistry for Process Metallurgy. Academic Piess TN673 A325 (1997). 

R. E. Reed-Hill, Physical Metallurgy Principles, Van Nostrand Reinhold, 1964. 

K. E. Easterling, Introduction to the Physical Metallurgy of Welding, Butterworth, 1983. 

Nonferrous metallurgy is as varied as the ores and finished products. Almost every thermal, chemical, and physical process known to engineers is in use. The general classification scheme that follows gives an understanding of the emissions and control systems aluminum (primary and secondary), beryllium, copper (primary and secondary), lead (primary and secondary), mercury, zinc, alloys of nonferrous metals (primary and secondary), and other nonferrous metals. 

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