The 1940′s
The conventional powder metallurgy took off in Germany shortly before the outbreak of World War II. In Sweden, it was later Höganäs AB (publ) who developed methods to obtain pure iron powder from the high purity Swedish ore by reduction. This pure iron powder was then pressed and heat treated (sintered) to small mechanical components, such as parts of sewing machines. The components which were manufactured by the powder was of a non-fully dense material, which meant that the material contained pores, which worked well in less-loaded applications.
After the war, the technologies quickly through the various alloys were added, creating new alloys with progressively better properties. In parallel, the technology to “atomize”, which means that a molten jet of metal crushed with the help of high pressure water? This resulted in an irregular shape to the metal that could be pressed into steel molds and subsequently heat treated to a certain density, however, still with pores.
The 1950′s
The high growth rate over the subsequent decades was driven by the automotive industry began using powder metal components for certain applications such as gears. The U.S. market was driven by its growth and large cars, which created large volumes of powder metal industry. This was followed by Europe and Japan following. Today includes a car between 5 and 15 kg components made of conventional powder metal.
The technology ofwater atomized metal powder cannot be used for high-alloy materials, such as stainless steel; there high material properties are required. Use of water for atomizing causes oxidation of alloying elements such as chromium, which adversely affects the material performance. Components manufactured from water atomized powder are always relatively porous and can in many respects, not compete with components made of solid materials. In parallel to the growth of the production of the powder from water atomizing began the development of atomization with pure gases such as argon, helium or nitrogen. The process resulted in a high-purity powder into the shape was spherical. The powders spherical shape makes it hard to press in open steel molds so it must be compacted and heat treated with more advanced technology. Specifically, the spherical powder is that each powder particle has an identical composition.
The 1960′s
During the late 1950s lasted at ASEA intensive development of press technology that would later be called Quintus press. This technology, which today is called HIP, Hot Isostatic Pressing, based on the gas under high pressure and high temperature press together a metal container filled with metal powder. HIP has been one of great importance in the manufacture of high-performance tool steels, for components for aerospace and corrosive elements in the offshore industry.
The 1970′s
In the 1970s positioned itself Sweden as a leading manufacturer of high-purity spherical metallic powders by the decision of Stora Kopparberg, now ErasteelKloster AB, to invest in powder manufacturing in Söderfors. While focused Crucible in the U.S. in a similar production of fully killed ingots, ie blanks of high speed steel by gas atomizing and Hot Isostatic Pressing.
Shortly after Anval AB was built in Torshälla, now Carpenter Powder Products AB, the world’s first major facility for gas atomizing of mainly stainless steel. Anval introduced during the eighties, major improvements in steel cleanliness, which later came to be used by other manufacturers. During the eighties were mainly skilled production extruded tubes from powders and hot isostatic pressing flanges etc. for the offshore.
In parallel, had also begun to produce very high quality products with the same technology for the manufacture of such turbine discs for the aerospace industry in the U.S.. A new process technology was now in place based on the gas even in a total of powder and HIP, which gave existing products as well or better material properties than products made with conventional methods.
The 1980′s – to the 2000′s
In the 1990′s, Uddeholm AB, now Böhler-Uddeholm AB, built a similar facility that the three above mentioned companies, however for tool steel. During the 80 – and 90′s a new technology was developed in California for the manufacture of small parts from powder to fully dense components. The method came to be called Metal Injection Mouilding, MIM, or in Swedishmetal injection molding, which uses the combination of known plastic molding techniques and a mix of plastic and metal powders as feedstock. After heat treatment is performed, a component with full density and the characteristics of solid steel. A commercial technology for producing small complex parts, up to 50-100 grams, in large series was now established.
These products replace the corresponding precision machined and cast parts and growth are currently very high, especially for stainless steel parts. Two techniques, one of the small details through MIM and one for large components through HIP, gave the market an equally good or better product at a competitive price. What was missing was a technique applicable for mass production of fully dense products in the mass range of 50-5000 grams. A method to mass produce fully dense products in the mass range of 50-5000 grams began in the mid 90′s developed by Scandinavian Powder Tech Inc. and Metal Process Systems SA in France. The method involves linking spherical powder grains, which could then be pressed into a steel tool and heat treated to full density.
The method was later to be called Scanpac ®. Thus was established a production technology that fills the gap between HIP and MIM methods. In the 2000s, continued Scandinavian Powder Tech AB development and discovered, among other benefits of combining Scanpac ® powder with high-speed compaction (HVC). In 2005 Metec Powder Metal AB was founded to establish industrial method and the combination of processes that evolved became known as MMS process in which Scanpac ® is an integral part.
