Invention Journal of Research Technology in Engineering & Management (IJRTEM) ISSN: 2455-3689 www.ijrtem.com Volume 1 Issue 4 ǁ June. 2016 ǁ PP 38-39
Analysis of Strength Relatively With Properties of both Pure Copper and Alloy Copper at Different Temperature Range 1
Deepak Sharma, 2Er. M.S. Milton 1
2
(Mechanical Department, L.R.I.E.T. Solan) (H.O.D. Mechanical Department, L.R.I.E.T. Solan)
ABSTRACT Copper and copper alloys retain a high degree of ductility and toughness at subzero temperatures. In fact, copper alloys become stronger and more ductile as the temperature goes down, retaining excellent impact resistance to 20 K (-253 C or -424 F). On high temperatures the properties of pure copper and alloy copper are to be analyzed at a temperature range from room temperature to about 550oC. The depreciation in Strain Hardening Exponent `n`, strengthening coefficient `A`, yield and ultimate strength for both pure copper and alloy copper has to be observed with rise in temperature. The Ductility or percentage elongation will also be analyzed with increase or decrease in temperature for both pure & alloy copper. The characteristic equation for both of the tested materials will be developed, which can be used to check the effect of temperature on copper and its alloys. Keywords: Copper, Ductility, Hardness, strengthening coefficient, tensile strengths. 1. Introduction Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile, semi-precious metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal alloys. The metal and its alloys have been used for thousands of years. In the Roman era, copper was principally mined on Cyprus, hence the origin of the name of the metal as сyprium (metal of Cyprus), later shortened to сuprum. Its compounds are commonly encountered as copper salts, which often impart blue or green colors to minerals such as turquoise and have been widely used historically as pigments[8]. Architectural structures built with copper corrode to give green verdigris. Decorative art prominently features copper, both by itself and as part of pigments. Today it is the most frequently used heavy nonferrous metal. The main grades of raw copper used for cast copper base alloy are : The copper which is used for electrical purposes having not less than 99.9% copper. The oxygen content could be of the order of 0.40%, Pb and Fe should be less than 0.005% each Ag 0.002% and Bi less than 0.001%. Deoxidized copper having not less than 99.85% Cu, less than 0.05% As, 0.035 Fe, and 0.003% Bi, other elements may be of the order of 0.005% P, 0.01% Pb, 0.10% Ni, 0.003% and 0.005% Ag and Sb respectively. Arsenical deoxidized copper having 0.45 As, 0.04% P, and rest all copper, is used for welded vessels and tanks. There are some properties of copper as shown in the table below[9]. Table 1.1 The Properties of Copper [9] Chemical Symbol:
The Properties of Copper Cu
Mineral: Relative density:
most commonly found as chalcopyrite 8.96
Hardness:
2.5-3 on Mohs scale
Malleability: Ductility:
High High
Melting point:
1083°C
Atomic Mass:
64
The yield strength of cold-rolled high yield (H01) copper is significantly higher than standard cold rolled (H00) copper, up to 33,000 p.s.i. This allows the use of 12 ounce high yield copper in many applications where 16 ounce cold rolled copper is normally used[10].
| Volume 1| Issue 4 |
www.ijrtem.com
| June 2016| 38
Analysis Of Strength Relatively With Properties Of Both Pure Copper And Alloy Copper At Different Temperature Range
Temper Designation Standard 060 Soft H00 Cold-Rolled 1/8 Hard H01 Cold-Rolled, high yield 1/4 Hard H02 Half Hard H03 Three quarter Hard H04 Hard
30 32
Table 1.2 mechanical properties of copper [10] Mechanical Properties of copper Tensile Strength (Ksi) Min. Max. 38 40
Yield Strength (Ksi) Min. -20
34
42
28
37 41 43
46 50 52
30 32 35
2. Objective The objective of this research work is to detect the behavior of pure copper & its alloys at high temperatures in between (Room Temperature to about 550oC) temperature range and then find out the following: 1. The Effect of high temperature on tensile strengths (yield & ultimate). 2. The ductility at high temperature. 3. To determine the stress & strain values. 4. The value of strengthening coefficient & work hardening exponent. 4. Plot the graphs and curves. 5. Derive the equations of curves with the help of curves fitted. 6. Analyze and determine the results. 3. Conclusion In this research we will define the values of ductility, strain hardening exponent `n` , ultimate and yield strength for both pure copper and alloy copper at different temperatures i.e. room temperature to about 550oC. So that we can use these properties of copper to us it under different atmospheric conditions and varying temperatures
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
REFERENCES Nagarjuna s., srinivas m., “High temperature tensile behavior of a Cu-1.5% Ti alloy”, International journal of material science and engineering, A335, (2002), 89-93. Luo Anhua, Shin S. Kwang, Jacobson L. Dean,”high temperature tensile properties of W-Re- ThO2 alloy”, Internationl Journal of material science and engineering A148,(1991), 219-229. Radovic M., Barsoum M.W., El-Raghy T., Seidensticker J., Widerhorn S., “Tensile properties of TiSiC2 in the 25-1300.C temperature range, ACTA Material, 48,(2002) 45-459 . Nagarjuna s., srinivas m., “elevated temperature tensile behavior of a Cu-4.5 Ti alloy”, international journal of materials science and engineering, A406,(2005),186-194. Nagarjuna s., srinivas m., “Grain refinement during high temperature tensile testing of prior cold worked and peak aged CuTi alloy”, Evidence of superplasticity”, material science and engineering,A 498 (2008) 468-474. Sadhu singh, Strength of materials in S.I. units, Khanna, 1992. Tiryakioglu Murat, Advances in the metallurgy of aluminum alloy, ASM International, 2001. www.discoveryharbour.com/commodies/copper/introduction_to_copper. www.australianminesatlas.gov.au/education/down_under/copper/properties.html. www.copper.org/applications/architecture/arch_dhb/technical-discussion/fundamentals/intro.html
| Volume 1| Issue 4 |
www.ijrtem.com
| June 2016| 39