I. Materials of Precious Metals
(1) Platinum: It is a rare and expensive natural pure white metal. It is one of the most rare precious metals for jewelry in the world. The annual supply of platinum is only 5% of gold. It has almost twice the strength of gold and 30 times the strength of gold. Platinum is white, natural and pure. Its purity is over 90%. It is natural and often wears without fading. PT900 means platinum jewelry with a purity of 90%, and pt950 means platinum jewelry with a purity of 95%.
(2) K gold: K gold refers to the alloy of gold and other metals mixed together, because its English is karatgold, so it is abbreviated as K gold. Precious metal part, pure gold is 24k, but pure gold is too soft to make watches. It must be mixed with other metals to enhance hardness. Generally, silver, copper and palladium are the main metals, but no matter what kind of metal is mixed, the proportion of pure gold is 75%. With the high ratio of gold, silver and copper, five different colors of materials can be produced. The content of copper can be expressed by n. For example, red gold with the highest content of copper is expressed by 5n, while platinum is correctly said to be white K gold.
(3) Silver: Silver is an ancient precious metal. It is the most used material for pocket watches in the eighteenth century and before. 925 represents the purity of silver and is the highest purity of silver. Silver is an active metal, which reacts easily with sulphur in the air and produces a black oxide layer, which makes silver black. Nowadays, it is far inferior to gold in surface application because it is easy to lose luster due to water, moisture and other reasons.
II. Other Metal Materials
(1) Semi-gold: It is made of stainless steel and 18K gold. It shows unique double-color aesthetic feeling.
(2) Gold cladding: The surface is stainless steel, covered with a layer of gold alloy, which is rolled into a whole by mechanical rolling. Its thickness is measured in micron, and 1 micron is equal to 1/1000 millimeter. Up to 10 to 15 microns in thickness, generally only 2 to 3 microns.
(3) Electroplating: Electroplating is a common surface decoration method in modern watches. The electroplating skills emerged in the 1970s. Because electroplating is stable on average, it is cheaper than gold wrapping and is not easy to fall off, and there is no possibility of discoloration and rust of forged yellow shell, so both of them will soon be eliminated from the market.
(4) Copper: In watches, copper is the best thing. It is cheap and easy to process. It is important to use in the machine core. At present, most of the machine core is made of brass alloy splint. Usually the color of the machine core we see is yellow and white. The yellow machine core is usually coated with titanium oxide, and the white machine core is coated with zinc and nickel alloy.
(5) Steel: steel, chromium and nickel, fine steel, chromium and nickel, stainless steel processing difficult, corrosion resistance and wear resistance are better than the former, the surface can be electroplated or not electroplated, only polishing or sandblasting, sanding treatment, forming different consequences of the appearance of a three-dimensional sense.
(6) Titanium metal: Titanium metal is gradually emerging under the lead of all-steel watches. Its material is called "aviation age" metal.
What is titanium? Titanium is found in the earth's crust, and its appearance can be bright and lustrous metal, or silver-gray, dark-gray powder. Titanium is a lightweight, hard, heat-resistant and cold-resistant metal with an oxide film on its surface, which can prevent wear and corrosion.
(7) Tungsten-titanium alloy: first, the powder of tungsten carbide and titanium carbide is pressed into the embryo by 1000 Pa pressure, then die-casting die, and then sintered into a high density component at 1450 degrees Celsius in a special furnace. Finally, after several processes and polishing with diamond powder, the sparkling tungsten-titanium alloy is made, which has good wear resistance.
(8) Tungsten steel: high hardness, wear resistance, clear appearance, bright and clean, known as "wear resistant material". The utility model can be combined with steel to make a ring mouth of the case or a watch band or grain, which can increase the wear resistance and decoration property of the surface of the case and the belt.
(9) Precision ceramics: Precision ceramics are smooth, wear-resistant, and do not hurt the skin. The important component is zirconia, which can obtain good processing performance under certain temperature conditions. Then through advanced processing methods, it can produce beautiful case and watch band. It can also show richness and nobility through special methods and various colors.
(10) High-tech ceramics: After injecting extremely delicate zirconia or titanium carbide powders into the mould under high pressure, the powders are bonded into ceramic parts in a sintering furnace at 1450 degrees Celsius, and then polished with diamond powder to produce high-tech ceramics with unique luster.
(11) High-tech lanthanum: Rare rare earth lanthanum is crushed and refined into particles, and the coarse embryo is put into the furnace and compressed at high temperature and high pressure. Its hardness is higher than that of tungsten-titanium alloy and high-tech ceramics. It is not easy to wear and tear, and emits mysterious light.
(12) Blue steel: Blue steel is a kind of steel formed by special firing process, so it emits a blue halo color. Blue steel is important for pointers. In addition to its beauty, it has antioxidant properties.