Iron Powder Parts

Iron Powder Parts

The most used of all metals, iron and iron alloys make up 95% of all of the metal tonnage produced worldwide with 500million tones mined each year and another 300million tones recycled. This can be attributed to the ease of production as well as the abundance of available iron. Iron makes up 5% of the Earth's crust and nearly 35% of the Earth's total mass; it is the most copious element on the planet. When crushed, this metal can be used alone or in the creation of unique alloys. As powder metallurgy heats raw materials to temperatures just below the melting point in order to compress and combine them, iron powder parts retain all of the desirable attributes of the pure metal regardless of mixing. Metallurgy utilizes the unique properties of iron to produce solid metal parts with the same qualities. These powder metal parts are used in a variety of industries. Electronic, ventilation, architectural, construction, automotive, energy and transport production all employ iron components such as structural and support beams, filters, bearings and braking components. The use of press-and-sinter processes when forming iron parts is popular as it results in little waste. As much as 97% of the raw iron used in manufacturing ends up in the finished parts. Although iron is necessary for human well being, caution should be taken when handling the powder as chronic inhalation can lead to the development of siderosis and lung cancer.

There are three basic steps to powder metallurgy, the process used to create iron powder parts. First, any of a number of techniques including atomization, flaking, pulverization, chemical reduction, and electrolytic are used to reduce the initial raw iron to a fine dust or powder.  Specific amounts of this powder are then placed into the compaction die or mold where pressure is applied from both above and below in precise amounts relevant to the specific materials and intended use of the finished product. After the resulting form is ejected from the die, sintering is used to fuse the powder particles together. The parts are placed on a moving belt which draws them through a controlled-atmosphere furnace, heating the compressed powder to just below the melting point of the raw materials. Iron has a relatively high melting point of 2786 degrees Fahrenheit. Sintering occurs at about 2/3 of this temperature or 1858 degrees Fahrenheit. In this manner, the mechanical bonds of raw iron are converted into metallurgical bonds creating solid mass from the powder. While powder metallurgy results in objects close to the finished product, a variety of secondary processes may be used to create application specific iron powder parts. Secondary operations include sizing, coining, infiltration, heat treating, machining, plating, drilling, grinding, reaming and resin impregnation.