Alloy: Difference between revisions
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An '''alloy''' is a combination of metals or of metals and other elements. | An '''alloy''' is a combination of metals or of metals and other elements. | ||
== Examples == | |||
;{{wp|Crown gold}} | ;{{wp|Crown gold}} | ||
: A 22 {{wp|karat|karat (kt)}} gold alloy used for English & UK gold coins from 1526 (Henry VIII) to 1914 (as currency), and since then for trade and bullion coins. ({{frac|22|24}} gold, {{frac|2|24}} copper) | : A 22 {{wp|karat|karat (kt)}} ({{frac|916|2|3}} fine) gold alloy used for English & UK gold coins from 1526 (Henry VIII) to 1914 (as currency), and since then for trade and bullion coins. ({{frac|22|24}} gold, {{frac|2|24}} copper) | ||
: 𝜌 = {{alloy|Au=22/24|Cu=2/24}} g/㎝³ | |||
;{{wp|Sterling silver}} | ;{{wp|Sterling silver}} | ||
: A 925 {{wp|fineness|fine}} silver alloy used for English & UK silver coins from before 1158 (Henry II) to 1919. (92.5% silver, 7.5% copper) | : A 925 {{wp|fineness|fine}} silver alloy used for English & UK silver coins from before 1158 (Henry II) to 1919. (92.5% silver, 7.5% copper) | ||
: 𝜌 = {{alloy|Ag=.925|Cu=.075}} g/㎝³ | |||
;{{wp|Britannia silver}} | ;{{wp|Britannia silver}} | ||
: An 11 {{abbr|℥|line1=troy ounce, |line2=1 ℥ = ¹⁄₁₂ ℔ (troy pound)}} 10 {{abbr|ʤ |line1=pennyweight, |line2=1 ʤ = ¹⁄₂₀ ℥ (troy ounce) |line3=1 ʤ = ¹⁄₂₄₀ ℔ (troy pound)}} silver alloy required in England for “wrought plate” (non-monetary silversmithing) from 1697–1720 to inhibit {{wp|coin clipping}} and melting. ({{frac|23|24}} silver, {{frac|1|24}} copper) | : An 11 {{abbr|℥|line1=troy ounce, |line2=1 ℥ = ¹⁄₁₂ ℔ (troy pound)}} 10 {{abbr|ʤ |line1=pennyweight, |line2=1 ʤ = ¹⁄₂₀ ℥ (troy ounce) |line3=1 ʤ = ¹⁄₂₄₀ ℔ (troy pound)}} (958 fine) silver alloy required in England for “wrought plate” (non-monetary silversmithing) from 1697–1720 to inhibit {{wp|coin clipping}} and melting. ({{frac|23|24}} silver, {{frac|1|24}} copper) | ||
: 𝜌 = {{alloy|Ag=.958333|Cu=.041667}} g/㎝³ | |||
; | ;“standard silver” (US) | ||
: A 900 fine silver alloy used for US coins from | : A 900 fine silver alloy used for US coins from ____ to 1964. | ||
: 𝜌 = {{alloy|Ag=.9|Cu=.1}} g/㎝³ | |||
;“standard gold” (US) | |||
: A 900 fine gold alloy used for US coins. | |||
: 𝜌 = {{alloy|Au=.9|Ag=.033|Cu=.067}} g/㎝³ | |||
=== Density === | === Density === | ||
Revision as of 19:26, 29 October 2018
An alloy is a combination of metals or of metals and other elements.
Examples
- Crown gold
- A 22 karat (kt) (916 2⁄3 fine) gold alloy used for English & UK gold coins from 1526 (Henry VIII) to 1914 (as currency), and since then for trade and bullion coins. (22⁄24 gold, 2⁄24 copper)
- 𝜌 = 17.61 g/㎝³
- Sterling silver
- A 925 fine silver alloy used for English & UK silver coins from before 1158 (Henry II) to 1919. (92.5% silver, 7.5% copper)
- 𝜌 = 10.36 g/㎝³
- Britannia silver
- An 11 ℥ 10 ʤ (958 fine) silver alloy required in England for “wrought plate” (non-monetary silversmithing) from 1697–1720 to inhibit coin clipping and melting. (23⁄24 silver, 1⁄24 copper)
- 𝜌 = 10.42 g/㎝³
- “standard silver” (US)
- A 900 fine silver alloy used for US coins from ____ to 1964.
- 𝜌 = 10.32 g/㎝³
- “standard gold” (US)
- A 900 fine gold alloy used for US coins.
- 𝜌 = 17.47 g/㎝³
Density
- ᴍ = material constituent
- 𝜌 = density (i.e. g/㎝³)
- 𝐴ᵣ = atomic weight
- 𝑤 = mass fraction (i.e. 9⁄10, .900 or 90%)
- 𝑎𝑡٪ = atomic percent
- Alloy (general)
| 𝜌Alloy | = | 1 | |||||||||||
|
- Au-Ag
- 𝜌Au-Ag = 𝜌Au 𝑤Au + 𝜌Ag 𝑤Ag − 4 exp(0.005 𝑤Au) 𝑤Au 𝑤Ag
- Au-Cu
- 𝜌Au-Cu = 𝜌Au 𝑤Au + 𝜌Cu 𝑤Cu − 5 exp(0.01 𝑤Au) 𝑤Au 𝑤Cu
- Ag-Cu
- 𝜌Ag-Cu = 𝜌Ag 𝑤Ag + 𝜌Cu 𝑤Cu − 0.12 exp(0.02 𝑤Cu) 𝑤Ag 𝑤Cu
- Au-Ag-Cu
- 𝜌Au-Ag-Cu = 1.004 𝑎𝑡٪Au 𝜌Au + 1.03 𝑎𝑡٪Ag 𝜌Ag + 0.096 𝑎𝑡٪Cu 𝜌Cu + x − y
- x = 0.35 ( cos(45+0.45 𝑎𝑡٪Au) + cos(45+0.45 𝑎𝑡٪Ag) + sin(𝑎𝑡٪Au) )
- y = 0.005 (𝑎𝑡٪Au+𝑎𝑡٪Ag) cos(0.9 𝑎𝑡٪Cu) + 0.2 cos(3.2 𝑎𝑡٪Cu)
-
𝑎𝑡٪ᴍ₁ = 𝑤ᴍ₁ 𝐴ᵣᴍ₁ 𝑤ᴍ₁ 𝐴ᵣᴍ₁ + 𝑤ᴍ₂ 𝐴ᵣᴍ₂ + 𝑤ᴍ₃ 𝐴ᵣᴍ₃ + ⋯
- Crown gold
| g/cm³ | 17.607 |
|---|---|
| ℔/in³ | 0.6361 |
| ℔/ft³ | 1099.2 |
- Crown gold
17.606787714237
- Fine gold
17.303181909145
References
- Kraut, J.C.; Stern, W.B. (June 2000) “The Density of Gold-Silver-Copper Alloys and its Calculation from the Chemical Composition”. Gold Bulletin, Vol. 33, Iss. 2, pp. 52–55. Springer-Verlag. doi:https://doi.org/10.1007/BF03216580.