Friday, May 17, 2019
Brass heat treatment
Copper in sensitive form has found its significant use only in electrical applications. But with the continued consider of copper, the addition of other metals called alloys was developed which enhanced its various properties. Now, polar Copper-based alloys were widely used in incompatible aspects of engineering and manufacturing. One of the best known and is widely used is the Copper-Zinc admixture or daring. (De Garmo, Black, Kohser, 1997) daringes according to Yu Lakhtin (1979) argon binary and multiple-component alloys based on copper with which the main component is zinc. Below is the phase diagram of Copper-Zinc Alloy at different Cu-Zi percentage and temperature. The commercial value of Brass is in its ? and ? +? phases. At these two different phases, different characteristics were distinct. Their distinction according to Lukhtin (1979) depended on Zinc content from 48% to 50%. The single-phase or ? -brasses were characterized by Lukhtin (1979) as can be readily worked in both the hot and cold conditions while the two-phase ? +? brasses be hot-worked at temperatures corresponding to the regions of the ? or ?+? phases. He also described ? +? brasses as having higher loudness and comport resistance but slight ductility. According to him, ? +? brasses were often alloyed with Al, Fe, Ni, Sn, Mn, Pb and other elements. And the addition of these alloying elements, excerpt Ni, reduces Zi solubility in Cu and promotes the formation of ? -phase. Further he wrote, the addition of alloying elements, except Lead, raised the strength and hardness of brass but reduced its ductility. Lead improved the machinability and antrification properties of brasses. According to De Garmo, et. al, Copper-based alloys are special Kly set through a system of numbers standardized by the Copper Development Association (CDA) which was select later by the American Society for Testing and Materials (ASTM), Society of Automotive Engineers (SAE), and the US goernmen t. Brasses were classified into molded and plaster bandage brasses. According to Lakhtin (1979), wrought brasses are used to make sheets, band stock, tubing, wire and other semi-fabricated products and casting brasses for making foundry castings. Owen Ellis (1948) further classified Brasses casting alloys into Red Brass, Leaded Red Brass, Semi-Red Brass, Leaded Semi-Red Brass, jaundiced Brass, Leaded Yellow Brass, High-Strength Yellow Brass (Manganese Bronze), Leaded High-Strength Yellow Brass (Leaded Manganese Bronze), Silicon Brass, provide Brass, Tin-Nickel Brass, Nickel Brass (Nickel Silver) and Leaded Nickel Brass (Leaded Nickel Silver). In his classification, Red Brasses consisted 2%-8% zinc, less 0.5% three, and with tin less than the zinc the homogeneous amount consisted the Leaded Red Brass except that channelize is everyplace 0. 5% Semi-Red Brass consisted 8%-17% zinc, less than 6% tin, and less than 0. 5% consume the same amount consisted the Leaded Semi-Red Bra ss except that film is over 0. 5% Yellow Brass consisted over 17% zinc, less than 6% tin, under 2% total of aluminum, manganese, nickel, iron, or silicon, and with less than 0. 5% lead the same constitutes for Leaded Yellow Brass except for lead which is over 0.5% High-Strength Yellow Brass consisted of over 17% zinc, over 2% total of aluminum, manganese, tin, nickel and iron, under 0. 5% silicon, under 0. 5% lead and less than 6% tin Leaded High-Strength Yellow Brass has the same constituents except that lead is over 0. 5% Silicon Brass has over 0. 5% silicon and over 5% zinc Tin-Nickel Brass has over 6% tin, over 4% nickel and with zinc more than tin Nickel Brass has over 10% zinc, with nickel in amount sufficient enough to give white color, and with lead under 0.5% and Leaded Nickel Brass has the same but with lead over 0. 5%. From these differed subject of Copper-Zinc Alloys different properties were possessed which gave them different uses. Ellis (1948) also wrote that tThe d ifferent required properties of Brass such as conduction and hardness can be secured through heat treatment, Below is a table of the different compositions, properties and uses of common Copper-Zinc Alloys. Works Cited De Garmo, P. , Black, J., Kohser, R. (1997). Materials and processes in manufacturing. (8th Ed. ). Upper Saddle River, NJ Prentice-Hall International, Inc. Ellis, O. (1948). Copper and copper alloys. Cleveland, Ohio American Society for Metals. Lakhtin, Y. (1979). applied science physical metallurgy and heat treatment. (Weinstein, N. , Trans. ). Moscow MIR Publishers. Mayers, J. Visual library. Retrieved Jan. 29, 2007 from http//www. sv. vt. edu/classes/MSE2094_NoteBook/96ClassProj/pics/Cu_Zn1. gif.
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