Powder metallurgy, PM or sintering, is a productive process based on the compacting and sintering of metal powder to produce pieces with complex shapes. Despite being complex the shapes are very high quality with narrow tolerances and are relatively inexpensive to make.
The pieces are produced in two phases. Firstly the metallic powder is deposited by means of gravitational force into a mould made by the tooling. The press then physically fuses the powder particles closing the cavity with the punch and the core pins by applying high pressure unidirectionally. This forces the powder to acquire the shape of cavity made by the toolkit. Once ejected, the piece that has been pressed is transported to a sintering furnace to acquire the physical characteristics needed.
The specific tooling used for this process is due precisely to the productive process. This is as much owing to the core pins as the pins which must slide with the least amount of fluctuation possible by the punch and in turn, the die, to give the piece its final shape. The shape of the tools must have smooth contours with edges tangent to the radiuses and tolerances of 0.001mm in order for the tools to be as close fitting as possible. Additionally, due to the high pressures and friction of the process, adherence is the greatest obstacle when attempting to prolong the life of the tool. On one hand this can be achieved is by applying materials to the tools that have the greatest benefits against wear, like tungsten carbide, and on the other hand surface finishes must be perfect, with an Ra of less than 0.5.
Tools subjected to an intense wear due to friction need a perfect surface finish -Ra 0.5 or less- and must combine high hardness with the
_ MATERIALS: CW 12% Co Fine grain 1.3 μm / 10% Co Micrograin 0.7 μm / 7,5% Co Micrograin 0.7 μm / ASP 23 CPM 9V / VANADIS 4 EXTRA.
_ COATING: TIN
Very slim tools that must keep their profile along the entire length and have high resistance to friction. Surface finish is of vital importance in avoiding material adhering to it so a Ra 0.5 or less is required.
_ MATERIALS: CW 12% Co Fine grain 1.3 μm / 10% Co Micrograin 0.7 μm / 7,5% Co Micrograin 0.7 μm / CPM 9V, ASP23, ASP 20/60
_ COATING: TIN