2E001 “Technology” according to the General Technology Note for the “development” of equipment or “software” specified by 2A, 2B or 2D.
Note: 2E001 includes “technology” for the integration of probe systems into coordinate measurement machines specified by 2B006.a.
2E002 “Technology” according to the General Technology Note for the “production” of equipment specified by 2A or 2B.
2E003 Other “technology”, as follows:
b. “Technology” for metal‑working manufacturing processes, as follows:
1. “Technology” for the design of tools, dies or fixtures specially designed for any of the following processes:
a. “Superplastic forming”;
b. “Diffusion bonding”; or
c. ‘Direct‑acting hydraulic pressing’;
2. Technical data consisting of process methods or parameters as listed below used to control:
a. “Superplastic forming” of aluminium alloys, titanium alloys or “superalloys”:
1. Surface preparation;
2. Strain rate;
3. Temperature;
4. Pressure;
b. “Diffusion bonding” of “superalloys” or titanium alloys:
1. Surface preparation;
2. Temperature;
3. Pressure;
c. ‘Direct‑acting hydraulic pressing’ of aluminium alloys or titanium alloys:
1. Pressure;
2. Cycle time;
d. ‘Hot isostatic densification’ of titanium alloys, aluminium alloys or “superalloys”:
1. Temperature;
2. Pressure;
3. Cycle time;
1. ‘Direct‑acting hydraulic pressing’ is a deformation process which uses a fluid‑filled flexible bladder in direct contact with the workpiece.
2. ‘Hot isostatic densification’ is a process of pressurising a casting at temperatures exceeding 375 K (102°C) in a closed cavity through various media (gas, liquid, solid particles, etc.) to create equal force in all directions to reduce or eliminate internal voids in the casting.
c. “Technology” for the “development” or “production” of hydraulic stretch‑forming machines and dies therefor, for the manufacture of airframe structures;
d. Not used since 2017;
e. “Technology” for the “development” of integration “software” for incorporation of expert systems for advanced decision support of shop floor operations into “numerical control” units;
f. “Technology” for the application of inorganic overlay coatings or inorganic surface modification coatings (specified in column 3 of the following table) to non‑electronic substrates (specified in column 2 of the following table), by processes specified in column 1 of the following table and defined in the Technical Note.
Note: The table and Technical Note appear after 2E301.
N.B.: This table should be read to specify the “technology” of a particular Coating Process only when the Resultant Coating in column 3 is in a paragraph directly across from the relevant Substrate under column 2. For example, Chemical Vapour Deposition (CVD) coating process technical data are included for the application of silicides to carbon‑carbon, ceramic and metal “matrix” “composites” substrates, but are not included for the application of silicides to ‘cemented tungsten carbide’ (16), ‘silicon carbide’ (18) substrates. In the second case, the resultant coating is not listed in the paragraph under column 3 directly across from the paragraph under column 2 listing ‘cemented tungsten carbide’ (16), ‘silicon carbide’ (18).
2E101 “Technology” according to the General Technology Note for the “use” of equipment or “software” specified by 2B104, 2B109, 2B116, 2B119 to 2B122 or 2D101.
2E201 “Technology” according to the General Technology Note for the “use” of equipment or “software” specified by 2B007.b., 2B007.c., 2A225, 2A226, 2B201, 2B204, 2B206, 2B207, 2B209, 2B225 to 2B233, 2D201 or 2D202.
2E301 “Technology” according to the General Technology Note for the “use” of goods specified by 2B350 to 2B352.
C. Pack cementation (see A above for out‑of‑pack cementation) (10) Carbon‑carbon, Ceramic and Metal “matrix” “composites” Silicides Carbides Mixtures thereof (4)
Beryllium and Beryllium alloys Borides Dielectric layers (15) Beryllium
Refractory metals and alloys (8) Aluminides Silicides Oxides Carbides
G. Ion Implantation High temperature bearing steels Additions of Chromium Tantalum or Niobium (Columbium)
Titanium alloys (13) Borides Nitrides
Beryllium and Beryllium alloys Borides
Cemented tungsten carbide (16) Carbides Nitrides
TABLE — DEPOSITION TECHNIQUES: NOTES
1. The term ‘coating process’ includes coating repair and refurbishing as well as original coating.
2. The term ‘alloyed aluminide coating’ includes single or multiple‑step coatings in which an element or elements are deposited prior to or during application of the aluminide coating, even if these elements are deposited by another coating process. It does not, however, include the multiple use of single‑step pack cementation processes to achieve alloyed aluminides.
3. The term ‘noble metal modified aluminide’ coating includes multiple‑step coatings in which the noble metal or noble metals are laid down by some other coating process prior to application of the aluminide coating.
4. The term ‘mixtures thereof’ includes infiltrated material, graded compositions, co‑deposits and multilayer deposits and are obtained by one or more of the coating processes specified in the Table.
5. ‘MCrAlX’ refers to a coating alloy where M equals cobalt, iron, nickel or combinations thereof and X equals hafnium, yttrium, silicon, tantalum in any amount or other intentional additions over 0.01% by weight in various proportions and combinations, except:
a. CoCrAlY coatings which contain less than 22% by weight of chromium, less than 7% by weight of aluminium and less than 2% by weight of yttrium;
b. CoCrAlY coatings which contain 22 to 24% by weight of chromium, 10 to 12% by weight of aluminium and 0.5 to 0.7% by weight of yttrium; or
c. NiCrAlY coatings which contain 21 to 23% by weight of chromium, 10 to 12% by weight of aluminium and 0.9 to 1.1% by weight of yttrium.
6. The term ‘aluminium alloys’ refers to alloys having an ultimate tensile strength of 190 MPa or more measured at 293 K (20°C).
7. The term ‘corrosion resistant steel’ refers to AISI (American Iron and Steel Institute) 300 series or equivalent national standard steels.
8. ‘Refractory metals and alloys’ include the following metals and their alloys: niobium (columbium), molybdenum, tungsten and tantalum.
9. ‘Sensor window materials’, as follows: alumina, silicon, germanium, zinc sulphide, zinc selenide, gallium arsenide, diamond, gallium phosphide, sapphire and the following metal halides: sensor window materials of more than 40 mm diameter for zirconium fluoride and hafnium fluoride.
10. Category 2 does not include “technology” for single‑step pack cementation of solid airfoils.
11. ‘Polymers’, as follows: polyimide, polyester, polysulphide, polycarbonates and polyurethanes.
12. ‘Modified zirconia’ refers to additions of other metal oxides (e.g., calcia, magnesia, yttria, hafnia, rare earth oxides) to zirconia in order to stabilise certain crystallographic phases and phase compositions. Thermal barrier coatings made of zirconia, modified with calcia or magnesia by mixing or fusion, are not controlled.
13. ‘Titanium alloys’ refers only to aerospace alloys having an ultimate tensile strength of 900 MPa or more measured at 293 K (20°C).
14. ‘Low‑expansion glasses’ refers to glasses which have a coefficient of thermal expansion of 1 x 10‑7 K‑1 or less measured at 293 K (20°C).
15. ‘Dielectric layers’ are coatings constructed of multi‑layers of insulator materials in which the interference properties of a design composed of materials of various refractive indices are used to reflect, transmit or absorb various wavelength bands. Dielectric layers refers to more than four dielectric layers or dielectric/metal “composite” layers.
16. ‘Cemented tungsten carbide’ does not include cutting and forming tool materials consisting of tungsten carbide/(cobalt, nickel), titanium carbide/(cobalt, nickel), chromium carbide/nickel‑chromium and chromium carbide/nickel.
17. “Technology” for depositing diamond‑like carbon on any of the following is not included:
magnetic disk drives and heads, equipment for the manufacture of disposables, valves for faucets, acoustic diaphragms for speakers, engine parts for automobiles, cutting tools, punching‑pressing dies, office automation equipment, microphones or medical devices or moulds, for casting or moulding of plastics, manufactured from alloys containing less than 5% beryllium.
18. ‘Silicon carbide’ does not include cutting and forming tool materials.
19. Ceramic substrates, as used in this entry, does not include ceramic materials containing 5% by weight, or greater, clay or cement content, either as separate constituents or in combination.
TABLE — DEPOSITION TECHNIQUES: TECHNICAL NOTE
Processes specified in Column 1 of the Table are defined as follows:
a. Chemical Vapour Deposition (CVD) is an overlay coating or surface modification coating process wherein a metal, alloy, “composite”, dielectric or ceramic is deposited upon a heated substrate. Gaseous reactants are decomposed or combined in the vicinity of a substrate resulting in the deposition of the desired elemental, alloy or compound material on the substrate. Energy for this decomposition or chemical reaction process may be provided by the heat of the substrate, a glow discharge plasma, or “laser” irradiation.
N.B. 1: CVD includes the following processes: directed gas flow out‑of‑pack deposition, pulsating CVD, controlled nucleation thermal deposition (CNTD), plasma enhanced or plasma assisted CVD processes.
N.B. 2: Pack denotes a substrate immersed in a powder mixture.
N.B. 3: The gaseous reactants used in the out‑of‑pack process are produced using the same basic reactions and parameters as the pack cementation process, except that the substrate to be coated is not in contact with the powder mixture.
b. Thermal Evaporation‑Physical Vapour Deposition (TE‑PVD) is an overlay coating process conducted in a vacuum with a pressure less than 0.1 Pa wherein a source of thermal energy is used to vaporise the coating material. This process results in the condensation, or deposition, of the evaporated species onto appropriately positioned substrates.
The addition of gases to the vacuum chamber during the coating process to synthesise compound coatings is an ordinary modification of the process.
The use of ion or electron beams, or plasma, to activate or assist the coating’s deposition is also a common modification in this technique. The use of monitors to provide in‑process measurement of optical characteristics and thickness of coatings can be a feature of these processes.
Specific TE‑PVD processes are as follows:
1. Electron Beam PVD uses an electron beam to heat and evaporate the material which forms the coating;
2. Ion Assisted Resistive Heating PVD employs electrically resistive heating sources in combination with impinging ion beam(s) to produce a controlled and uniform flux of evaporated coating species;
3. “Laser” Vaporisation uses either pulsed or continuous wave “laser” beams to vaporise the material which forms the coating;
4. Cathodic Arc Deposition employs a consumable cathode of the material which forms the coating and has an arc discharge established on the surface by a momentary contact of a ground trigger. Controlled motion of arcing erodes the cathode surface creating a highly ionised plasma. The anode can be either a cone attached to the periphery of the cathode, through an insulator, or the chamber. Substrate biasing is used for non line‑of‑sight deposition;
N.B.: This definition does not include random cathodic arc deposition with non‑biased substrates.
5. Ion Plating is a special modification of a general TE‑PVD process in which a plasma or an ion source is used to ionise the species to be deposited, and a negative bias is applied to the substrate in order to facilitate the extraction of the species from the plasma. The introduction of reactive species, evaporation of solids within the process chamber, and the use of monitors to provide in‑process measurement of optical characteristics and thicknesses of coatings are ordinary modifications of the process.
c. Pack Cementation is a surface modification coating or overlay coating process wherein a substrate is immersed in a powder mixture (a pack), that consists of:
1. The metallic powders that are to be deposited (usually aluminium, chromium, silicon or combinations thereof);
2. An activator (normally a halide salt); and
3. An inert powder, most frequently alumina.
The substrate and powder mixture is contained within a retort which is heated to between 1,030 K (757°C) and 1,375 K (1,102°C) for sufficient time to deposit the coating.
d. Plasma Spraying is an overlay coating process wherein a gun (spray torch) which produces and controls a plasma accepts powder or wire coating materials, melts them and propels them towards a substrate, whereon an integrally bonded coating is formed. Plasma spraying constitutes either low pressure plasma spraying or high velocity plasma spraying.
N.B. 1: Low pressure means less than ambient atmospheric pressure.
N.B. 2: High velocity refers to nozzle‑exit gas velocity exceeding 750 m/s calculated at 293 K (20°C) at 0.1 MPa.
e. Slurry Deposition is a surface modification coating or overlay coating process wherein a metallic or ceramic powder with an organic binder is suspended in a liquid and is applied to a substrate by either spraying, dipping or painting, subsequent air or oven drying, and heat treatment to obtain the desired coating.
f. Sputter Deposition is an overlay coating process based on a momentum transfer phenomenon, wherein positive ions are accelerated by an electric field towards the surface of a target (coating material). The kinetic energy of the impacting ions is sufficient to cause target surface atoms to be released and deposited on an appropriately positioned substrate.
N.B. 1: The Table refers only to triode, magnetron or reactive sputter deposition which is used to increase adhesion of the coating and rate of deposition and to radio frequency (RF) augmented sputter deposition used to permit vaporisation of non‑metallic coating materials.
N.B. 2: Low‑energy ion beams (less than 5 keV) can be used to activate the deposition.
g. Ion Implantation is a surface modification coating process in which the element to be alloyed is ionised, accelerated through a potential gradient and implanted into the surface region of the substrate. This includes processes in which ion implantation is performed simultaneously with electron beam physical vapour deposition or sputter deposition.