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Platinum–iridium alloys are alloys of the platinum group precious metals platinum and iridium. Typical alloy proportions are 90:10 or 70:30 (Pt:Ir). These have the chemical stability of platinum, but increased hardness. The Vickers hardness of pure platinum is 56 HV while platinum with 50% of iridium can reach over 500 HV.
The only three verifications occurred in 1889, 1948, and 1989. For instance, the US owns five 90% platinum / 10% iridium (Pt‑10Ir) kilogram standards, two of which, K4 and K20, are from the original batch of 40 replicas distributed in 1884. [Note 4] The K20 prototype was designated as the primary national standard of mass for the US. Both of ...
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A member of the platinum group metals, iridium is white, resembling platinum, but with a slight yellowish cast. Because of its hardness, brittleness, and very high melting point , solid iridium is difficult to machine, form, or work; thus powder metallurgy is commonly employed instead. [ 12 ]
The platinum-group metals [a] (PGMs) are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 and 6). [1] The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum.
Platinum is a chemical element; it has symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish platina, a diminutive of plata "silver". [7] [8] Platinum is a member of the platinum group of elements and group 10 of the periodic table of ...
Elastic properties describe the reversible deformation (elastic response) of a material to an applied stress.They are a subset of the material properties that provide a quantitative description of the characteristics of a material, like its strength.
AA-8000: used for electrical building wire in the U.S. per the National Electrical Code, replacing AA-1350. [1]Al–Li (2.45% lithium): aerospace applications, including the Space Shuttle