Intermediate layer between component and top layer; causes good bonding to base material, can reduce stresses by equalizing thermal expansion coefficients of GW and top layer.
Atmospheric plasma spraying; thermal spraying in which the plasma jet operates under normal ambient conditions.
Polymer blend, enables powder plasticization and mold filling during injection molding. Critically affects the green strength of the part. Binder composition determines debinding process.
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Soldering process in which the melting temperature of the solder is between 450 and 900°C.
The thermal removal of the binder during heating to sintering temperature. Active soldering Soldering process that uses active solders capable of reacting even with ceramics or other materials that are difficult to wet.
A ridge of injection molding compound thrown up along the parting line, caused by excessive injection pressure, poor mold tolerances, or segregation of binder and powder.
The final pressing of a sintered component to set defined surface structures, flatness or roughness.
The measure of the ability to remove binder without carbon contamination of the powder. Carbon control is quantified by the carbon content of the PIM parts after sintering and its uniformity across the batch, between different batches and different feedstock batches. Certain materials require the lowest possible carbon content (austenitic stainless steel, titanium), whereas others require a defined percentage (quenched and tempered steel, tool steel, carbide).
The partial removal of the plasticizer by heating in an atmosphere containing depolymerizing substances. Classical is the decomposition of polyacetal in a nitrogen atmosphere loaded with nitric acid.
A hydrostatic molding process for processing plasticizer-added ceramic powders at comparatively low temperatures and pressures.
The fabrication of a part exactly to final geometry with no additional need for follow-up operations.
The fabrication of a part nearly to final geometry with minimal need for downstream operations.
Coarse grain annealing is used to set a microstructure that enables subsequent machining production processes to be carried out at higher cutting speeds. In most cases, coarse grain annealing is followed by normalizing to convert the material into a tougher state.
The change in porosity caused by pressing or sintering divided by the initial porosity.
The formation of bonds between polymer chains with consequent increased stiffness and strength of the polymer. An example of cross-linked polymers are thermosetting plastics, which harden on initial heating.
A process step between molding and sintering in which the bulk of the plasticizer is removed by heat, solvent, catalysis, or other methods.
Cracking in an injection molded part, often not apparent until after debinding or sintering.
The mass of a body divided by its volume, typically expressed in g/cm3 or as a ratio to theoretical (100%) density.
The repeatability of the final geometries of a PIM fabrication expressed by the scatter. Often quantified by the standard deviation (or a multiple thereof) of a dimension, normalized by that dimension and expressed as a percentage (e.g., 0.5%).
Processes required after sintering on a component to set the required dimensions or properties.
The operations required after sintering of a PM component to set the required dimensions or properties. Typical examples include machining, polishing, heat treating, straightening, or electroplating.
Additive that removes surface oxides from components, allowing wetting and spreading of the solder.
Soldering process in which no additional flux is used and oxide removal is accomplished by reducing gases or a decomposition.
The narrowest point in the flow channel; the entry opening for the injection molding compound into the injection mold cavity.
The strength of the component in the injection-molded ("green") state.
Binder or polymer cures when heated to a temperature at which cross-linking of the polymer chains takes place.
Soldering process in which the melting temperature of the solder is above 900°C.
A process to completely densify sintered PIM components by using highly compressed gas at high temperature. Usually used only for high performance components.
A heated mold cavity in which the molding compound is kept liquid between injection molding cycles to avoid sprues and runners.
Flux-free brazing process carried out in reducing or inert gas atmospheres, e.g. hydrogen or argon. Components are bare after brazing.
The process of filling the pores of a component with a deeper-melting metal or alloy.
The mixture of powder and binder used for injection molding.
Zone between base material and layer.
Sintering at a temperature at which solid and liquid components are simultaneously present as a result of chemical reactions, partial melting, or the formation of eutectic melts. Often used for sintering of stainless steels and alloys containing phosphorus, boron, copper or silicon.
A hydrostatic shaping process for processing metal powders mixed with plasticizing agents at comparatively low temperatures and pressures.
Thermo-chemical process to enrich the surface with nitrogen. This increases the wear resistance, fatigue strength and corrosion resistance of workpieces. A basic distinction is made between gas nitriding and plasma nitriding.
Thermo-chemical process for enriching the surface with nitrogen and carbon. The aim of the process is to increase wear resistance, often in combination with an improvement in corrosion resistance (see post-oxidation). Nitrocarburizing can take place in a gas, in a salt bath, or in plasma.
In normalizing, the material is returned to its original state. This can be used to eliminate coarse grain structures or forming structures in particular. Regardless of the original state, normalizing produces a fine-grained microstructure with roundish grains of the same size.
The total amount of voids in a PM component. Most PIM materials have less than 5% porosity after sintering.
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Process for applying a thin oxide layer to an existing nitride layer, for the purpose of increasing corrosion resistance. This also gives the components an aesthetic dark gray appearance.
An important method for binder extraction, especially for wax-polymer binders. In this process, the components are packed in a fine-grained powder and heated to the melting temperature of the wax. The molten wax is drawn into the surrounding powder by capillary forces.
A hydrostatic molding process for processing plasticizer-added powders at comparatively low temperatures and pressures.
The heating of a component to a temperature below the usual sintering temperature for the purpose of increasing strength for subsequent handling or machining. The temperature is usually above that required to completely burn off the binder.
Sintering with the aid of external pressure. Often performed following vacuum sintering by increasing pressure in the furnace with the aim of closing any residual porosity.
Sealing layer in turbines or compressors into which the rotor blades cut during operation. Are applied to minimize the gaps caused by design and thus achieve higher efficiencies.
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The linear marking appearing on a component after injection moulding at the joint of the two halves of the mould.
The decrease in the size of a component that occurs during the sintering process.
A shallow indentation on the surface of an injection molded component. Forms during cooling as a result of premature freezing of the gate. Can be corrected by higher injection pressure.
The thermal process which bonds and compacts compacted powders. Most of the mechanical, magnetic, or other properties of a PIM component are adjusted during the sintering process.
Possibly substrate adapted to the component geometry to support and assist the PIM component during the debinding and sintering process.
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Filler material needed for soldering.
Closed-material joining process in which the joining partners remain solid and only the solder becomes molten.
LG is a heat treatment process used especially for austenitic stainless steels or Ni-based alloys. The material is held at temperature from about 1000°C to 1250°C for 15 minutes to several hours (depending on the workpiece dimensions) and then quenched.
The extraction of the binder or parts thereof by washing with a solvent. This is done by immersion or exposure to solvent vapors.
The inlet opening for the injection molding compound into the injection mold. The gate is usually filled by the nozzle and is tapered for easy demolding. The sprue fills the sprue manifold, which fills the gate.
Part of the feed channel in the injection mold. Lies between the sprue and the gate (the entry opening into the injection mold cavity).
Stress relief annealing aims to reduce internal stresses (residual stresses) caused by previous manufacturing processes (e.g. forming, machining, welding, hardening, etc.). Stress relieving of steels is carried out in the temperature range 550 to 650°C.
The liquid phase sintering of fully alloyed powder above the melting temperature, forming liquid phase inside the powder particles.
The application of high pressure and elevated temperature to heat a solvent above the critical temperature for binder removal. In powder injection moulding, carbon dioxide is most commonly used for this purpose.
The extraction of the binder or parts thereof by heating. The classical processes were based on slow heating in air over a period of days.
Vacuum annealing is an annealing process that is carried out in a vacuum furnace and thus protects the components from oxidation as far as possible.
Flux-free soldering process carried out in a vacuum atmosphere of 10-2-10-6mbar. Components are bright after vacuum brazing.
The extraction of the binder or parts thereof by heating in a vacuum. Usually carried out with the assistance of a carrier gas to convey the extracted binder to the pumps.
Embedding of the sprayed layers in negative pressure (vacuum), in order to fill the cavities in porous structures and to obtain more precise preparation results.
A family of binders based on water-soluble polymers. Debinding can therefore take place in water. Common are polyethylene oxide, ployvinyl alcohol and polyethylene glycol.
Often gelatinising binders which solidify after injection moulding due to the formation of long molecular chains. Other types are based on water saturated with silicates, which forms glass when solidifying.
A term used to describe binders based on low molecular weight polymers and waxes. The polymers are typically polyethylene, polypropylene or copolymers such as ethylene vinyl acetate. These are the classic PIM binders.
A linear mark or defect on the part surface where the flow fronts have joined during injection molding.
Spreading of the solder on the surface.
