Refractory metals alloy properties

More than half of the elements in the Periodic Table react with silicon to form one or more silicides. The refractory metal and noble metal silicides ate used in the electronics industry. Silicon and ferrosilicon alloys have a wide range of applications in the iron and steel industries where they are used as inoculants to give significantly improved mechanical properties. Ferrosilicon alloys are also used as deoxidizers and as an economical source of silicon for steel and iron. 

Because several of the superalloys contain very little iron, they are closely related to some of the non-ferrous alloys. Some of the second- and third-row transition metals possess many of the desirable properties of superalloys. They maintain their strength at high temperatures, but they may be somewhat reactive with oxygen under these conditions. These metals are known as refractory metals, and they include niobium, molybdenum, tantalum, tungsten, and rhenium. 

It should be noted that it is difficult to obtain models that can accurately predict thermal contact resistance and rapid solidification parameters, in addition to the difficulties in obtaining thermophysical properties of liquid metals/alloys, especially refractory metals/al-loys. These make the precise numerical modeling of flattening processes of molten metal droplets extremely difficult. Therefore, experimental studies are required. However, the scaling of the experimental results for millimeter-sized droplets to micrometer-sized droplets under rapid solidification conditions seems to be questionable if not impossible,13901 while experimental studies of micrometer-sized droplets under rapid solidification conditions are very difficult, and only inconclusive, sparse and scattered data are available. 

Among the refractory metals, perhaps none are as widely exploited for commercial applications as titanium. From golf clubs to shavers, titanium is now pervasive throughout our modern world. Although some of the proposed applications may be suitably classified as hype, the broad appeal for titanium alloys is due to its favorable properties such as high strength/weight ratio and superior corrosion resistance. Titanium is also readily available from a number of mineral sources it is the sixth most abundant metal, behind Al, Fe, Cu, Zn, and Mg. 

To identify suitable materials for an acid complex such as Hl, one can begin by surveying materials applicable to the individual acid/chemical. Table 4.5 to table 4.7 list the corrosion properties of various materials in I2, HI acid, and H2SO4.12 is a strong oxidizer, especially in liquid form at high temperature. The corrosion rates of a number of corrosion-resistant materials in I2 at 300 and 450°C are listed in table 4.5. Even though the data show that gold and platinum are stable in an I2 environment, they have been found to dissolve in HI. Refractory metals such as Ta and Nb alloys are probably the best candidates within the l2-rich environment in Section 1. 

The most commonly used methods for the preparation of ultrathin oxide films are (1) direct oxidation of the parent metal surface, (2) preferential oxidation of one metal of choice from a suitable binary alloy, and (3) simultaneous deposition and oxidation of a metal on a refractory metal substrate. The detailed procedures for (1) and (2) are discussed elsewhere [7,56,57] procedure (3) is discussed here in detail. Preparation of a model thin-film oxide on a refractory metal substrate (such as Mo, Re, or Ta) is usually carried out by vapor-depositing the parent metal in an oxygen environment. These substrate refractory metals are typically cleaned by repeated cycles of Ar sputtering followed by high-temperature annealing and oxygen treatment. The choice of substrate is critical because film stoichiometry and crystallinity depend on lattice mismatch and other interfacial properties. Thin films of several oxides have been prepared in our laboratories and are discussed below. 

Molybdenum (Mo) is a silvery-white, hard, fairly ductile, refractory metal suitable for alloys that are required to exhibit a combination of high strength and rigidity at temperatures as high as l,650°C. Selected properties of molybdenum are listed in Table 2, in comparison with the respective properties of tungsten and... 

The effect of rhenium on the properties of refractory metals has been a research topic of discontinuous relevance since its discovery in the 1950 s [1, 2], Several works have been devoted to the mechanical property enhancement seen in VIb group transition metals when solid solution alloyed with rhenium [3-12], In the 1970 s the works of... 

Among his research interests are investigation of the cathode materials for the lithium-ion batteries, physical-chemical properties of low-temperature ionic liquids and electrochemistry of refractory metals in ionic liquids. Recently he has been taking part in the research and optimization on the industrial scale of processes of Zn, Zn-Fe and Zn-Ni alloy deposition. 

Lambert, J.B. (1991) Refractory metals and alloys. In ASM Handbook of Metals Series 9th ed. Vol. 2 Properties and Selection of Nonferrous Alloys and Special-Purpose Materials. American Society of Metals (ASM), Materials Park, OH, pp. 557-585. 

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