Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C25/00—Profiling tools for metal extruding
  • B21C25/02—Dies
  • B21C25/025—Selection of materials therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C25/00—Profiling tools for metal extruding
  • B21C25/04—Mandrels
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C19/00—Alloys based on nickel or cobalt
  • C22C19/03—Alloys based on nickel or cobalt based on nickel
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C19/00—Alloys based on nickel or cobalt
  • C22C19/07—Alloys based on nickel or cobalt based on cobalt
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D

Definitions

• the present invention relates to an extrusion tool or die for the extrusion of metallic material, in particular a material of aluminium or alloys thereof, or other non-ferrous metals such as Cu and alloys thereof.
• Extrusion is a process used to create solid or hollow objects of a fixed cross sectional profile. The material is pushed through the die of the desired cross section.
• the two main advantages of the extrusion process over other manufacturing processes is its ability to create very complex cross-sections and finished parts with an excellent surface finish.
• the dies are, depending of course on the material being extruded and temperature etc., subjected to wear and numerous attempts have been made to improve the life time of extrusion dies for example by selecting suitable die materials, heat treatment and/or coating of the die with different types of coating such as CVD or nano particle type coatings.
• an extrusion device for the extrusion of hollow or semi- hollow sections of metal, in particular aluminium.
• the device has at least one mandrel support projecting into the die opening where the mandrel head is a special insert type which is held in place on a mandrel support by a connecting device.
• US-04773251 is related to a 2 part die, whereof one part includes the bearing and the other being the support.
• the specificity of this solution appears to be that the two die parts are atomically bonded using powder metallurgy technology.
• the "support” part (the one that does not carry the bearing) is relatively vaguely defined in terms of material selection as a "tough non-ductile heat resistant steel of a composition different from the metallic material of the bearing holding part".
• JP-06315716 further relates to an extrusion die with a tool comprising a material made of a Ni base alloy and having hardness after heat treatment of more than HRC 33.
• the purpose of using such alloy is to prevent the penetration of Zn into the tool, i.e.
• CN-201287153 shows an aluminium profile extrusion die where the die tools, i.e. the parts forming the extrusion profile opening are replaceable and are made from a wear resistant material.
• an extrusion die where the lifetime is quite considerably extended and where the cost of replacement and maintenance accordingly is reduced.
• Tests performed in several aluminium extrusion plants of the applicant shows that the selection of Ni-base super alloys as die material according to the invention reduces sever cracking and improves the die lifetime from one/two hundred extruded billets to thousand and more extruded billets before replacement of die parts or maintenance is needed.
• the invention is characterized by the features as defined in the enclosed independent claim 1.
• Fig. 1 shows an example of an extrusion die according to the invention, a) assembled in cross section, b) the same in expanded view, Fig. 2 shows in larger scale a cross section part of one of the die cavities shown in Fig.1 a).
• Fig. 3 Shows a Manson-Coffin diagram depicting the linear relationship, on a log- log plot, of plastic strain range versus cycles to failure of the most common tool steels, employed for extrusion dies, with the fatigue properties of a superalloy according to the invention.
• extrusion is a process used to create solid or hollow objects of a fixed cross sectional profile.
• the attached figures show an example of an extrusion tool or die 1 for extruding hollow profiles which will be further explained in the following.
• the extrusion die 1 as shown in Fig. 1 a) and b) includes one bridge die body 2 and one plate die body 3, each provided with two cavities 4, respectively 5 and each cavity further defining openings with inserts 6, 7.
• the die as shown in Fig. 1 represents what is defined as being a two cavity die capable of extruding two profiles in parallel at the same time. Extrusion dies may however be of one or three or more cavity type depending on the type, shape (design) and size of the die opening forming the extruded product as well as the capacity of the extrusion equipment (ram and block - not shown in the figures).
• Fig. 2 shows in larger scale and in cross section one of the die cavities 4, 5 shown in Fig.1 a).
• the two die bodies 2, 3 are, in an assembled condition whereby a mandrel part 10 on the bridge die body 2 partly protrudes into the opening of the cavity 5 in the die plate 3 such that an opening 11 is formed between the mandrel and cavity opening 5 in the die 3.
• the material being extruded is pressed through this opening 1 1 thereby forming the shape of the final, extruded hollow product.
• the mandrel 10 is made of a separate mandrel insert 6 attached to the bridge die body 2 by means of a screw 8.
• the opening in the die plate 3 is made of a separate bearing insert 7, as well being attached to the die plate 3 by means of second screws 9.
• the bearing insert 7 may as an alternative be thermally shrunk fit into a recess in the die plate 3 opening 5.
• the fundamental idea of the present invention is the selection of different materials and the combined utilization of these in the appropriate zones of the extrusion die, fitting with the thermo-mechanical solicitations on one side and the tribological solicitations on the other side.
• the first "modulus" of the die which includes the bridge body 2 and/or die plate body 3 depending as stated above on whether it is a hollow or solid profile, is made of a
• the Superalloys are based either on a) Nickel, b) Cobalt or c) Iron.
• the Nickel, Cobalt and Iron based Superalloys ranges may respectively be defined as follows: Nickel based superalloys: Ni (min 39 % max 78 %), Fe (min 0% max 36%), Cr (min 12% max 25%), Al (min 0% max 5%), Co (min 0% max 20%), Mo (min 0% max 10%), Nb (min 0% max 5%)
• Co (min 34% max 50%), Ni (min 10 % max 29 %), Fe (min 3% max 26%), Cr (min 3% max 22%), Al (min 0% max 6%), Nb (min 0% max 3%), W (min (0% max 15%)
• Iron based superalloys Fe (min 42% max 74%), Ni (min 0 % max 38 %), Cr (min 0% max 20%), Al (min 0% max 5%), Co (min 0% max 15%), Mo (min 0% max 5%), Nb (min 0% max 5%)
• Superalloys or high-performance alloy, are alloys that exhibit excellent mechanical strength and creep resistance at high temperatures, good surface stability, and corrosion and oxidation resistance.
• Superalloys develop high temperature strength through solid solution or precipitation strengthening: to a first approximation the elevated temperature strength of a superalloy depends upon the amount and distribution of the strengthening intergranular second phase, which is ⁇ ' in the case of Nickel-based Superalloys and carbides in the case of cobalt-base Superalloys.
• Creep resistance is dependent on reducing the speed of dislocations within the crystal structure.
• the body centred cubic gamma prime phase [Ni3(AI,Ti)] present in nickel and nickel-iron Superalloys, presents a barrier to dislocations.
• Chemical additions such as Aluminium and Titanium promote the creation of the gamma prime phase ( ⁇ ').
• the gamma prime phase size can be finally controlled by annealing.
• solid-solution-strengthened alloys are expected to have strong resistance to fatigue cracking due to an increased resistance to slip and an enhanced strain hardening capacity.
• high temperature fatigue may be thought of a cyclic creep rupture process. For this reason, the relationships between microstructure, creep deformation and fracture, previously described, are applicable.
• the strong resistance against environmental effects is provided by the formation of a protective oxide layer which is formed, by elements such as aluminium and chromium, when the metal is exposed to oxygen and encapsulates the material, and thus protecting the rest of the component.
• the alloys hereafter identified in table 1 by their UNS, ISO or AFNOR norms are examples falling into the above described families.
• the table contains, for indicative purpose one of the well-established trade-name of the alloys.
• NIMONIC® alloy 105 ISO NW 3021 NIMONIC® alloy 1 15 AFNOR NCK 15 ATD
• Table 1 primary list of High temperature performance Superalloys covered by the present invention. Additionally to the previous, the following alloys listed in table 2 and identified by their commercial names and detailed chemical compositions are also among the explicitly covered materials used for the first "modulus", i.e. the high thermo-mechanical solicitation area of the die. The materials listed in table 2 are part of the Ni-base Superalloys defined above : Denomination Ni Fe Cr Al Co Mo Nb Ti W Y203 Ce Si
• the following alloy identified by its trade-name and chemical composition is also among the explicitly covered materials used for the first "modulus", i.e. the high thermo-mechanical solicitation area of the die.
• table 3 is part of the Ni-base Superalloys defined above :
• the second modulus of the die which is/are the insert/s, i.e. the so-called bearings of inserts 6 and 7 (area of the die where the extruded profile takes its final shape) is manufactured of a wear resistant material.
• Such material could be any known wear resistant die material such as a high speed tool steel, a precipitation hardened steel or a high alloy hot-worked stee and alloys being obtained by a standard forging process, a spray forming technique or by powder metallurgy technology or any of such steel or material types provided with surface hardening through nitriding or similar process or by a surface coating technology such as chemical vapour deposition (CVD), Plasma assisted/Enhanced chemical vapour deposition (PACVD/PECVD), Physical vapour deposition (PVD) or other spraying processes (Flame Spray, Cold spray/high velocity, Plasma spray, high velocity oxyfuel Spray, etc..)
• - 2N is the number of reversals to failure (N cycles);
• Fig. 3 shows a linear relationship, on a log-log plot, of plastic strain range versus cycles to failure.
• the diagram permits to benchmark the fatigue behaviour of the most common tool steels, employed for extrusion dies, with the fatigue properties of a superalloy. It is clear that the superalloy, on equal terms of plastic strain applied at elevated temperature, shows a higher fatigue life than a tool steel. The results highlight the superior fatigue resistance of the superalloys and confirm the good adaptability of these materials for the realisation of the area of the die with a strong thermo- mechanical solicitation
• the present invention as defined in the claims is not restricted to the above two cavity die example for extruding hollow profiles based die inserts 6 and 7, but may be one or a three or more cavity type and also single or more cavity die plate for extruding solid profiles.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Extrusion Of Metal (AREA)
• Coating With Molten Metal (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

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• 2011
  • 2011-02-09 WO PCT/NO2011/000050 patent/WO2011099868A1/en active Application Filing
  • 2011-02-09 US US13/516,028 patent/US20130047692A1/en not_active Abandoned
  • 2011-02-09 KR KR1020127019743A patent/KR20120135214A/ko not_active Application Discontinuation
  • 2011-02-09 CA CA2788660A patent/CA2788660C/en not_active Expired - Fee Related
  • 2011-02-09 CN CN2011800058473A patent/CN102712021A/zh active Pending
  • 2011-02-09 JP JP2012552830A patent/JP2013519527A/ja active Pending
  • 2011-02-09 EP EP11742530A patent/EP2533917A1/en not_active Withdrawn

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