Application of the china spark plug electrode noble metals are iridium, platinum, nickel three, they have what characteristics? Iridium is a high hardness and brittle, silver-white platinum group transition metal, high temperature can be pressed into thin slices or drawing. Iridium is the second highest density element (inferior to osmium), iridium is the most corrosion-resistant and wear-resistant material even at the high temperature of 2000 ℃. Iridium in the alloy is more resistant to high temperatures and corrosion, such as china spark plug electrode is the use of iridium is the use of this feature. Platinum is a transition metal, density, scalability, color silver, metallic luster, hardness 4-4.5, the relative density of 21.45. The high melting point of 1773 ℃. As the melting point of platinum than iridium (2410 ± 40 ℃) is low, so the performance is inferior, but compared to the most common nickel alloy is still much stronger. Rich ductility, can be pulled into a very fine platinum wire, rolled into a very thin platinum foil. Chemical properties of a very stable, insoluble in strong acid and alkali, dense metal platinum at any temperature of the air are not oxidized. Nickel chemical symbol for the atomic number of 28, a magnetic, silver-white transition metal, the melting point of 1453 ° C. In the nature of nickel silicate ore or sulfur, arsenic, nickel compounds exist. Of tough, magnetic and good plasticity in the air is not oxidized, soluble in nitric acid. The general center of the nickel alloy spark plugs will be relatively thick, so after a period of time in the use of ignition stability will be worse. These three kinds of metal as the central electrode of the china spark plug are called iridium spark plug, platinum spark plug, nickel-copper alloy spark plug. Gasgoo has those all. Please login to see links and more information.