Alloys with Low Melting Temperature

An eutectic composition with low melting temperature is also shown. After Stadelmaier et al. (1984), the eutectic constituent found in the magnet alloys have 70 at% Nd with little boron. 

Because of its high range of temperatures as a liquid (from 29.8°C to 2,403°C), it is used in special types of high-temperature thermometers. It is also alloyed with other metals to make alloys with low temperature melting points. 

The technique of impregnation with low melting point alloy results in a freezing of the state of penetration in 3-dimensions amongst the pore spaces. An impregnated sample of powder can then be sectioned and polished and, if viewed on an SEM, affords a view of a 2-D random plane through the 3-D pore spaces. The alloy used melts at 47 C. Impregnation has been performed at around 60 C (in a hot water bath) so that samples are solid at room temperature. 

Oxides with low melting points exhibit high vapor pressure at high temperatures and become less protective. Refractory metal oxides such as M0O3, VO2, and WO3, have high vaporpressure at temperatures above 1000 °C. However, the volatility of these oxides does not contribute to the oxidation and is no concern of alloys if used in small quantities [7,8]. 

The softening temperature of the glass must also be compatible with the characteristics of the material to which it is joined. This requirement is somewhat difficult to meet for aluminum alloys, where the melting temperatures of the metals are relatively low for most glasses. Low... 

Of the many copper alloys, only 60/40 brass and its variants with a melting temperature of about 900 °C combine acceptable mechanical properties with a casting temperature low enough to give reasonable die life. The higher zinc content lowers the casting temperature and gives essential hot ductility. Small additions of silicon or tin improve fluidity tin also improves corrosion resistance. Aluminium is added to form a protective oxide film to keep the molten metal clean and reduce the attack on die materials. 

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