Glossary Terms for RPI WebsiteAbrasive Wear – Wear caused by the rubbing or scrapping of hard particles, such as carbides, across the surface of a substrate. This is a typical tool failure mode. The high micro-hardness of our coatings will protect against this type of wear.
Adhesion – The attractive molecular force that tends to hold together unlike bodies where they are in contact. When discussing coatings, adhesion refers to the strength of the bond between the coating and the substrate.
Adhesive Wear (Galling) – A condition whereby excessive friction between high spots results in localized welding with subsequent spalling and further roughening of the rubbing surfaces of one or both of the mating parts. This is a typical tool failure mode. The low coefficient of friction of our coatings protects against this type of wear.
Aluminum Oxide Coating (Al2O3) – A wear resistant CVD coating (not typically done as PVD) that forms an excellent thermal and chemical barrier between the tool and workpiece. Typically used on carbide inserts, aluminum extrusion tooling and resistance welding tips. This coating is used in several of our CVD multi-layer coatings.
Aluminum Titanium Nitride Coating (AlTiN) – A wear resistant PVD coating used for tools machining cast iron, high nickel and titanium alloys, hardened steels, stainless steels and more. This coating is also excellent in stamping and forming applications. Furthermore, as the temperature at the tool/work piece interface exceeds 1380° F, the aluminum uses oxygen from the air and converts the outer layer of the AlTiN to Al2O3, thereby creating an extremely hard and heat resistant layer.
Ångstrom (Å) – A unit of length equal to 10-10 meters, or 0.1 nanometer.
Boronizing - A thermo-chemical surface treatment in which boron atoms are diffused into the surface of a work piece to form borides (FeB2) with the base metal. The diffused coating layer (typically 10-200 microns in depth) provides a hard surface with a low coefficient of friction and a high temperature resistance. This coating can be used in forging applications, burner tubes and as a wear resistant coating for components.
Cathodic Arc Deposition – One of several methods for producing PVD coatings. This vacuum arc process generates the ions used for coating by forming an electrical discharge that is sustained primarily on the electrons and ions that originate from the cathodes used to produce the arc. The high ionization rate of this process makes it good general purpose coating process.
Chemical Vapor Deposition (CVD) – This high temperature coating process, as it relates to tooling applications, involves the deposition of a solid material onto a heated substrate via a chemical reaction from a gas phase. This process can be done in atmosphere or vacuum. Because this is a chemical bond, the bond strength is many times stronger than achieved through the PVD process. CVD is typically used for carbide inserts, forming tools and other high load applications. Due to the high processing temperature (1925° F), there are some material and tolerance limitations. Due to the high processing temperature, all tool steels and High Speed Steels (HSS) must be heat treated after this coating process.
Chipping – This type of tool damage is often associated with stresses within the tool substrate (especially at sharp edges), as well as general material brittleness. This is a typical tool failure mode. The low coefficient of friction of our coatings will allow sharp edges to cut more freely, thereby reducing stress-related chipping. Also, reducing material hardness (which increases toughness) and allowing the high micro-hardness of the coatings to provide wear resistance can reduce chipping.
Chromium Carbide Coating (CrC) – A PVD coating with good resistance to chipping and cracking. This coating is good for machining aluminum and titanium alloys, stamping and forming applications, and aluminum die-casting molding components. Chromium carbide (CrC) has a slightly higher micro-hardness than chromium nitride (CrN), and is one of the components of our Titankote™ C3 (CrN/CrC) multi-layer PVD coating.
Chromium Nitride Coating (CrN) – A PVD coating with good resistance to chipping and cracking. This coating is good for machining aluminum and titanium alloys, stamping and forming applications, and aluminum die-casting molding components. Chromium nitride (CrN) is one of the components of our Titankote™ C3 (CrN/CrC) multi-layer PVD coating.
Coefficient of Friction – The quotient obtained by dividing the value of the force necessary to move one body over another at a constant speed by the weight of the body. For example, if a force of 20 Newtons is needed to move a body weighing 100 Newtons over another horizontal body at a constant speed, the coefficient of friction between these two materials is 20/100 or 0.2.
Cohesion – The molecular force between particles within a body or substance that acts to unite them. When discussing thin-film coatings, this refers to the stability of the coating matrix.
Columnar Morphology – In the context of film formation, this refers to the morphology that develops with thickness due to the development of surface roughness due to preferential film deposition on high points on the surface. The columnar morphology resembles stacked posts, and the columns are not single grains.
Cracking/Fracturing – Also known as fatigue fracturing, this type of tool damage generally occurs when repeated or fluctuating stresses have a maximum value less than the tensile strength of the substrate: basically, the tool has been overloaded. This type of fracture is generally progressive, beginning as minute cracks that grow under the action of the fluctuating stress. This is a typical tool failure mode.
Decorative Coating – A coating whose function is decorative, so that the properties of interest are primarily color, color distribution and reflectivity. Since decorative coatings do not require the same properties, such as wear resistance, as a functional coating, they are typically less than one micron in thickness.
Diamond-Like Carbon (DLC) Coating – Diamond-like-carbon (DLC) coatings are formed when ionized and decomposed carbon or hydrocarbon species land on the surface of a substrate with energy typically 10-300eV. DLC films may possess exceptional mechanical (high hardness), optical (high optical band gap), electrical (high electrical resistivity), chemical (inert) and tribological (low friction and wear coefficient) properties and can be deposited at low substrate temperature (<200°C).
Such films are generally amorphous (i.e have no dominant crystalline lattice structure) and consist of a mixture of sp2 (trigonal structuring – graphite) & sp3 (tetrahedral structuring - diamond) phases.
Diffusion Coating – A coating process used to change the surface composition of a metallic material with (1) another metal or alloy employing heat or (2) exposure to a gaseous or liquid metal to effect diffusion into the basis metal.
Dry-Film Lubricant Coating – These coatings are used strictly for tribological reasons: reducing friction between moving parts. These coatings perform well due to their extremely low coefficient of friction. Our Dynamic Compound Deposition (DCD) coating process synthesizes numerous dry-film lubricant compositions.
Dynamic Compound Deposition (DCD) – This term is used to designate a family of proprietary low temperature coatings. The DCD process is used to synthesize numerous dry-film lubricant and wear resistant coating compositions. DCD is based on the principle of in situ mechanical activation and chemical transformation, and leads to considerably decreased friction coefficients and increased durability of the coating layers. DCD process is primarily suited to anti-friction, slide-wear, and high-load applications.
EMCAD (Electro-Magnetic Cathodic Arc Discharge) – This is the cathodic arc deposition process developed by Richter Precision, Inc. This system utilizes proprietary hardware and software for optimal coating conditions. A special hardware arrangement allows us to obtain coatings free of the macro-particles that are characteristic of the standard cathodic arc process.
Epitaxial Growth – As related to film formation, it refers to the growth of one crystal on another such that the growth of the deposited crystal is determined by the crystalline orientation of the underlying surface.
Functional Coating – A coating that improves the operational properties of a surface, such as wear resistance, lubricity, corrosion resistance, etc.
Hardness – A measure of the resistance of a material to surface indentation or abrasion. There is no absolute scale for hardness; therefore, to express hardness quantitatively, each type of test has its own scale of arbitrarily defined hardness. Indentation hardness can be measured by Brinell, Rockwell, Vickers, Knoop, and Scleroscope hardness scales.
Ion Beam Plating Deposition - One of several methods for producing PVD coatings. In this vacuum process, an electron beam is used to evaporate the source material in order to generate positively charged ions. The positively charged ions are attracted to the negative charge given to the tooling substrate, thereby depositing the coating layer.
Interface – In the context of film formation, it refers to the region of contact between two materials.
Interphase Material – In the context of film formation, this refers to the material at the interface that is formed by diffusion, reaction or co-deposition at the interface between the film and the substrate. The properties of this material are an important consideration in adhesion.
Magnetron Sputtering Deposition – One of several methods for producing PVD coatings. In this process, you sputter using a crossed-field electro-magnetic configuration to keep the ejected secondary electrons near the cathode (target) surface and in a closed path on the surface. This allows a dense plasma to be established near the surface so that the ions that are accelerated from the plasma do not sustain energy loss by collision before they bombard the sputtering target. They closed path can be easily generated on a planar surface or on any surface of revolution.
Medikote™ - Richter Precision, Inc.’s proprietary PVD coating processes specifically designed to meet the stringent quality requirements of the medical device manufacturing industry. The Medikote™ PVD coating processes emphasize traceability, critical process validation, frozen process control, inspection/certification, continuous improvement, service and delivery.
Micro-hardness – The hardness of a material as determined by forcing an indenter such as a Vickers or Knoop indenter into the surface of a material under very light load; usually, the indentations are so small that they must be measured with a microscope. Capable of measuring steep hardness gradients such as those encountered in thin-film coatings.
Micron (µm) – The millionth part of a meter; also called micrometer. Common methods for indicating one micron may be shown as 1 micron, .001 mm., or 1µm.
Molybdenum Disulfide Coating (MoS2) – A dry-film lubricant coating that can be deposited through numerous methods: RPI utilizes the DCD process. Molybdenum disulfide coating is typically used for tribological applications. It is also very useful when applied on top of PVD, CVD and TD coatings: the lower coefficient of friction supplied by the MoS2 can dramatically improve tooling performance.
Multi-Layer Coating – A coating consisting of two or more component layers of two or more different materials with clearly defined interfaces.
Nano-Layer Coating – These are coatings that consist of a hundreds of very thin (a fraction of a micron) layers of alternating chemical composition (for example AlTiN-CrN). The coatings are characterized by increased hardness, resistance to crack propagation, and overall improved performance.
Niobium Carbide Coating (NbC) – One of several coatings generated through the TD (TRD) process. Niobium carbide (NbC) is a great choice for heavy load applications like metal-forming, extrusion, cold-heading, etc. The TD (TRD) process has been shown to work particularly when forming stainless steels.
Plasma – A gas that contains an appreciable number of electrons and ions such that it is electrically conductive.
Plasma-Assisted CVD (PaCVD) – Also known as Plasma-Enhanced CVD (PeCVD), this is a CVD process where a plasma is used to assist in the decomposition and reaction of the chemical vapor precursor, thereby allowing the deposition to be performed at a significantly lower temperature than when using thermal processes alone.
Plastic Deformation – This is a permanent deformation in a tool substrate caused by a material’s insufficient yield strength for an application. This is a typical tool failure mode. A material and/or heat treating change will be required.
PVD (Physical Vapor Deposition) - Physical Vapor Deposition, or PVD, is a term used to describe a family of relatively low temperature (750° F) vacuum coating processes that involve the generation of positively charged ions through various methods. Reactive gases are introduced into the chamber to create various compounds. The positively charges ions are attracted to a negative bias given to the tool substrates. This attraction results in a dense thin-film layer with an extremely strong physical bond to the tool substrate.
Replikote™ - This is Richter Precision, Inc.’s proprietary PVD coating process specifically developed for highly polished, optical grade surfaces. This ultra-refined PVD process filters out all macro particles. This makes it possible to deposit a defect-free thin-film layer onto large optical surfaces, thereby replicating the existing surface finish. This process is typically used for plastic injection molding applications.
Richkote™ - This is Richter Precision, Inc.’s proprietary name for our decorative PVD coating processes. Our processes incorporate the latest in “in-line” decorative PVD coating: the service, quality, technology, and color varieties provided by RPI are unmatched within the industry. Our low-temperature PVD magnetron sputtering units can even coat chrome-plated ABS plastics.
Silicon Carbide Coating (SiC) – This coating can be deposited through numerous methods: RPI utilizes the DCD process. The high micro-hardness of silicon carbide (SiC) coating provides a wear-resistant layer to tooling. Silicon carbide is generally used in conjunction with a dry-film lubricant coating.
Stoichiometric Compound – A compound material which has the correct atomic ratios for all lattice sites to be occupied for the specific phase of the material.
Stoichiometry – The numerical ratio of atoms in a compound.
Substrate – The material, work piece, or substance on which a coating is deposited.
TD (Thermal Diffusion) - TD is also referred to as Thermo-Reactive Diffusion (TRD).This is a high temperature coating process for producing metal carbides (typically vanadium carbide) on the surface of a carbon-containing substrate through immersion in a chemically charged salt bath. The resulting bond is extremely strong, and makes this coating excellent for applications with a high contact load. TD (TRD) is typically used in many of the same applications as CVD coatings. However, there are some applications where TD (TRD) has shown itself to be superior: aluminum & zinc die-casting components, hot forging tools, and tools for stamping and forming stainless steels.
TDkote Tri Cplus™ - Richter Precision, Inc.’s proprietary name for our TD coating process. Our TDkote Tri Cplus™ coating process represents the next step forward for TD coating technology. Our TD process generates multiple complex carbides in the coating matrix in order to increase hardness, toughness, wear-ability, and lubricity.
Titanium Aluminum Nitride Coating (TiAlN) - A wear resistant PVD coating similar to AlTiN; however this coating has a higher percentage of titanium content. This coating is more ductile than AlTiN, thereby making it a better choice for roughing and interrupted cutting applications.
Titanium Carbide Coating (TiC) – This coating is typically deposited through the CVD process. The high hardness of this coating gives it excellent abrasion resistance. It is typically used in high load forming applications. It can be deposited as a mono-layer CVD coating, or as part of a multi-layer coating configuration. RPI has several CVD coatings utilizing this composition.
Titanium CarboNitride Coating (TiCN) – This coating is commonly deposited through both the PVD and CVD process. As a PVD coating, TiCN is recommended for machining high carbon steels, high silicon aluminums, and tool steels. As a CVD coating, the high hardness of this coating gives it excellent abrasion resistance in high load forming applications. It is generally deposited as a multi-layer PVD or CVD coating. RPI has several coatings utilizing this composition.
Titanium Nitride Coating (TiN) – This coating is deposited through both the PVD and CVD process: it is the most commonly processed PVD and CVD coating. As a PVD coating, TiN is a good general purpose coating, good for metal cutting, metal-forming, fine-blanking, plastic injection molds, etc. As a CVD coating, the high hardness of this coating gives it excellent abrasion resistance in high load forming applications. It can be deposited as a mono-layer PVD coating, or as part of a multi-layer PVD or CVD coating. RPI has several CVD coatings utilizing this composition.
Titankote™ - Richter Precision, Inc.’s proprietary name for our general purpose tool coatings. This name includes PVD processes (indicated with Titankote™ C… designations) and CVD processes (indicated with Titankote™ H… designations).
Torr – A unit of pressure, being the pressure necessary to support a column of mercury one millimeter high at 0° C and standard gravity, equal to 1333.2 microbars. We use this to measure the level of vacuum in our PVD coating vessels.
Tribo-kote™ - Richter Precision, Inc.’s proprietary name for the tribological coatings created through our Dynamic Compound Deposition (DCD) coating process.
Tribological Coating – Coatings designed to reduce friction and wear on contacting surfaces that move relative to each other (bearings, cams, gears, etc.).
Tungsten Disulfide Coating (WS2) – A dry-film lubricant coating that can be deposited through numerous methods: RPI utilizes the DCD process. Tungsten disulfide coating is typically used for tribological applications. It is also very useful when applied on top of PVD, CVD and TD coatings: the lower coefficient of friction supplied by the WS2 can dramatically improve tooling performance.
Vacuum Heat-Treating – Thermal treatment in a furnace that has been evacuated to partial pressure: this pressure may vary depending upon material. The vacuum process prevents oxidation of surfaces and decarburization. This process is used to heat treat tool steels and high speed steels after the CVD and TD (TRD) coating processes. Vacuum heat treating does not affect the coated surfaces.
Vanadium Carbide Coating (VC) – One of several coatings generated through the TD process. Vanadium carbide (VC) is a great choice for heavy load applications like metal-forming, extrusion, cold-heading, etc. The TD process has been shown to work particularly when forming stainless steels.
Vickers (HV) – This is a micro-indentation hardness test employing a 136° diamond pyramid indenter (Vickers) and variable loads, enabling the use of one hardness scale for all ranges of hardness. This is the scale commonly used to measure hard thin-film coatings.
Zirconium Nitride Coating (ZrN) – A good general purpose wear resistant PVD coating. This coating is recommended for machining cast iron and non-ferrous materials such as titanium, aluminum, copper, and brass.