Metal powder is compressed in a specially designed high-pressure mechanical, hydraulic or electric driven precision press, typically with 6 tons/cm2.
By use of massive pressure, the part will achieve the desired geometrical shape within the tool, but the strength will be limited. Post-press parts are called “green” parts.
The green part is transported to a special sintering furnace, where the part is heated / cooled in several steps, in a controlled gas protected atmosphere. The heating temperature is typically 200 degrees Celsius below the base material’s melting temperature. However, if increased strength is required the temperature can be increased further. The powder grains “melt” together in a so-called atomic diffusion process.
After the sintering process, the part is ready for use – or for undergoing one or more additional processes such as grinding, machining, calibration and / or surface treatments.
The final result is a finished part that may have a very complex geometry, narrow tolerances and good mechanical properties.
The production of powder metal parts is typically highly cost-efficient compared to machined, cast or even stamped parts.
There are, however, certain geometrical and mechanical limitations, so do not hesitate to ask us.
We have the expertise – and you are welcome to make use of it. The processes involved may seem complex and difficult to understand, but they are second nature to us. Let us help you get the decision you make to be a qualified one!
Already from the initial contact with FJ Sintermetal you will get access to our wide range of know-how in manufacturing of your specific component.
We will guide you all the way through the selection of manufacturing process and materials.
FJ Sintermetal knows that your key focus is consistent quality at lowest possible costs and when production is running, we will make sure to fullfill your demands on time every time.
The powder used in manufacturing sintered parts comprises a base powder to which lubricant and possibly alloying elements have been added.
The base powder is either a non-alloy or an alloyed steel powder, a stainless steel powder, or a bronze powder.
The exact composition of the powder is determined by the specific component requirements. FJ Sintermetal will formulate the powder combination in-house or in cooperation with our raw material suppliers.
FJ Sintermetal have through the years produced components to a wide range of industrial customers, so we can surely also find a solution that will fulfill your needs.
Making tools for powder pressing is very delicate and only for highly trained professionals.
FJ Industriesl has very skilled and experienced tool designers and tool makers in-house and our know-how in this field is superior.
In-house tool design and manufacturing make the time from initial contact to production short and we don’t have to seek external advice to provide you with a professional and cost efficient solution.
First the cavity (single or multi cavity) in the tool is automatically filled with a precision-measured quantity of powder. Then the powder mixture is pressed (500 – 700 Mpa), and the specific shape of the part is created by several moving tool parts.
The extreme pressing binds the powder grains mechanically, and the high pressure results in cold welding where the grains are in contact with each other.
Now we have what is known as a green metal powder part, and the part is than ejected from the tool and led away, after which the next filling takes place.
After pressing, the parts are sintered. Sintering is carried out in a continuous belt furnace that is heated to a temperature which causes the particles of the powder mixture to sinter together.
Both sintering and the subsequent cooling are carried out in a protective gas atmosphere. The furnace comprises three zones:
– the incineration zone, the sintering zone and the cooling zone.
The lubricant melts/evaporates at temperatures between 400-700° Celsius, so it has no influence on the sintering process itself.
The particles are sintered to form a cohesive unit at a temperature below the melting point of the material. During sintering the metallurgic properties of the part are adjusted by carefully controlling the atmosphere, time, temperature, and cooling rate. This ensures that the properties fulfill the requirements for the individual component.
To avoid damage due to oxidation of the parts when they leave the furnace, they are cooled in a controlled atmosphere. The strength of the sintered parts correspond to those of solid metal parts. If required, and depending on the use the part is intended for, sintered parts can be machined and treated in exactly the same way as solid metal parts, and we offer all traditional subsequent processes.
The sintered parts are ready for use when they leave the furnace. But we carry out additional treatment if required.
The list of additional treatment that we carry out;
Deburring – removing burrs and make a smooth surface
Coining and sizing – improving tolerances
Grinding and polishing – reducing surface roughness and improving tolerances
Machining – making threads and shapes which are not possible by pressing
Galvanizing – protection against corrosion
Heat treatment – improving hardness and strength
Oil impregnation – integrated lubricant
Painting – changing surface color
Welding and brazing – joining methods
Plastic impregnation – closing porosity
Steam treatment (black oxidizing) – closing porosity, increases surface hardness and changing color (black)
CO2 based cleaning – dry cleaning with supercritical carbon dioxide
We know that many of our customers prefer to place as many processes as possible with a single supplier. Regarding the additional treatments that we do not have in-house, we have very reliabale and highly qualified suppliers and we can offer you a turn key solution.
We carry out ongoing quality improvements in order to meet the demands of our customers and the market. Employees are included at all levels, on the basis of the philosophy that quality assurance is everybody’s responsibility. The quality department has an very up-to-date monitoring laboratory at its disposal where methods for process and final control are established based on analytical measurements and capability analysis.
FJ Industries is used to handling customer specific quality requirements and PPAP documentation is often part of our work.
Quality is a key issue within our business and you are always welcome to book a visit at one of our plants.
FJ Industries can manufacture extremely strong, high wear resistant metal components with the help of sinter forging.
This technology is especially suitable for cutting tool inserts within the forest industry.
The unique material properties are achieved due to the unique material composition and by densifying the metal powder, the parts get almost the same density as solid steel.
Sinter forging involves compacting metal powder in a cold state for the component, after which it is heated and pressed in a sealed tool.
FJ Industries invests time and money in innovation and project management
Give us a call or email us your initial sketch to improve design efficiency.
Do not hesitate to involve us in your projects on an early stage. Don’t waste time on designing components that are difficult or even impossible to produce in powder metal or casting.
We will always provide you the needed design advice within our technologies for free.
In addition to our own experts we have the ability to use ressources from our network within universities, other educational institutions, research institutes and suppliers.