Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/01—Alloys based on copper with aluminium as the next major constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/05—Alloys based on copper with manganese as the next major constituent

Definitions

• the invention relates to a method for producing a copper alloy, which is particularly suitable for mechanical, for example, by vibration, impact or shock loaded components, adjusted to the application of the components alloy properties and specifically with targeted improved, or optimally adjusted mechanical damping. Furthermore, the invention relates to such an alloy of particular composition and possible uses for the alloys obtained by the process.
• HIDAMETs High Damping METaIs
• high mechanical damping capacity is desirable for reducing vibration and noise reduction.
• Such alloys are therefore particularly suitable for the manufacture of marine propellers and pump housings, as well as for use in vibrating machines and for preventing vibration disturbances in various precision apparatuses and electronic instruments.
• the alloys are also suitable for use in various tools that are exposed to vibrations and / or shocks during operation, such as punches or dies in sheet metal forming or in lathes and milling machines.
• Ni-Ti alloy (“Nitinol”)
• Cu-Zn-Al alloys (“Proteus”)
• Mn-Cu alloys (Sonoston”
• Ni-Ti alloys must be produced consuming under vacuum and are also very expensive due to the alloying elements involved.
• nitinol Cu-Zn-Al alloys are much cheaper.
• the limited corrosion resistance and the tendency to brittle fracture behavior are significant disadvantages of these alloys.
• they are extremely severe in both the austenitic and the martensitic state to aging.
• Mn-Cu alloys have been specially developed for the manufacture of ship propellers.
• a technically interesting material alternative to the HIDAMETs described above are Cu-Al-Mn shape memory alloys. These materials also exhibit a thermoelastic martensite transformation.
• US Pat. No. 4,146,392 describes Cu-Al-Mn shape memory alloys containing, in addition to the main constituent copper, as alloy constituents 4.6 to 13% by weight of manganese and 8.6 to 12.8% by weight of aluminum, and good resistance to Have aging. These are alloys whose austenite-martensite transformation takes place at temperatures below 0 ° C. and whose shape memory effect is exploited, for example to produce pipe connection elements.
• the invention therefore an object of the invention to provide heavy-duty and corrosion-resistant HIDAMETs with a precisely adjustable even in the decisive for the intended application temperature range high damping capacity and a method for their production.
• the object of the invention is achieved by a method for producing a copper alloy with specifically improved mechanical damping, in particular for mechanically loaded components, which is characterized by the following steps: a) a composition for the alloy is selected and the
• Steps c) and d) may be repeated as many times as necessary until the desired adaptation of the transformation temperatures or intervals is achieved.
• composition for the alloy is selected from the components:
• the alloys obtained by the process according to the invention are otherwise produced by conventional melting and casting processes. Except as
• Cast alloy the alloy can also be used as wrought alloy.
• Alloy can be cold or hot form.
• the alloys described herein are particularly advantageous for all applications where a high mechanical damping capacity is required, i. especially for mechanically loaded components, devices or housings that are subject to vibrations, impacts or shocks.
• the alloys differ from Sonoston in significantly higher aluminum and significantly lower manganese contents.
• the high aluminum content improves the strength of the material according to the invention and at the same time increases its resistance to abrasion, erosion and cavitation.
• the reduced manganese concentration has a positive effect on the cast-technological properties of the alloy due to the reduction in the solidification interval.
• dense, oxide and warm crack-free casts can be produced with unit weights of several tons without quality problems.
• the proportions of the alloy components are usually varied, for. B. as described in more detail below. It has been found that the mechanical damping capacity, which frequently fluctuates greatly with variation of the composition, can be optimized and set to higher values by means of a targeted fine tuning of the contents of the individual alloy components than if only the martensitic region were preferred for better reproducible damping properties. as is usual in the prior art.
• the martensit austenitic transformation temperatures or the associated intervals Ms to MF and / or As adjusted to AF to a predetermined service or working temperature which will occur in the intended use of the alloy in a "component".
• component is intended to cover all conceivable practical applications and include both individual parts, such as more complex composite components, housings, machines and the like.
• Both the operating temperature and the working temperature can be medium temperatures, ie average values from a working or application area.
• both transition temperature intervals, the martensitic and the austenitic may be used to set to one or more different operating temperature ranges. The adjustment is made by varying the weight proportions of the above alloying ingredients during the melting of the alloy.
• nickel, iron, cobalt, zinc, silicon, vanadium, niobium, molybdenum, chromium, tungsten, beryllium, lithium, yttrium, cerium, scandium, calcium, titanium, phosphorus, zirconium, boron, nitrogen, carbon it is possible to specially adapt the properties of the alloy obtained by the process to the particular application.
• addition of nickel or silicon increases corrosion resistance and strength properties.
• Elements iron, vanadium, niobium, molybdenum, chromium, tungsten, yttrium, cerium, scandium, calcium, titanium, zirconium, boron are important for achieving grain refinement.
• Nitrogen and carbon together with transition elements improve the mechanical properties of the alloy obtained according to the invention.
• the aging resistance of the alloy in both austenitic and martensitic states is increased by the addition of cobalt.
• Beryllium and phosphorus protect the melt from oxidation.
• the alloy therefore preferably contains between 1 and 4% by weight of nickel.
• a preferred embodiment of the alloy contains between 11.6 and 12 wt .-%, preferably about 11, 8 wt .-% aluminum.
• manganese contents between 8 and 10 wt .-% are preferred in the alloy.
• the alloy may further preferably contain between 0.01 and 1% by weight of cobalt.
• the texture of the cast alloy is characterized by relatively large cast grains and is preferably grain-fined to achieve optimum mechanical properties.
• Boron additions between 0.001 and 0.05% by weight and / or chromium additions between 0.01 and 0.8% by weight and / or iron additions of 2 to 4% by weight are particularly effective for this purpose.
• the refinement can be carried out by adding rare earths up to 0.3% by weight.
• the alloy may further contain between 2 and 6% zinc.
• the alloys may preferably have Ms temperatures> 0 0 C, without the invention being limited thereto.
• the invention provides a significant improvement in the damping properties, since only by the invention, the optimal adjustment of these properties while taking into account other desired properties is possible.
• the inventive method allows the transformation temperatures in
• the invention further comprises a particularly composed copper alloy containing as alloy constituents more than 4% by weight of manganese, more than 10% by weight of aluminum, 0.01 to 0.8% by weight of chromium and singly or in total
• each element contains not more than 6% and ad 100 wt .-% copper.
• this new alloy for mechanically loaded components may have the further specifications as stated above and is also available by adjusting the martensite-austenitic transformation temperatures or the associated intervals Ms to Mp and / or As to AF to a predetermined service temperature of the component , as described above.
• the maximum values for the specific damping capacity occur in the alloy according to the invention during cooling from the austenite state in the range between Ms and MF and when heating from the martensite state between As and AF.
• the temperature in the middle of the martensitic or austenitic phase transition interval should be as close as possible to the operating temperature of components made from the alloy of the invention. It is therefore possible with the invention to produce alloys for specific predetermined service or operating temperatures or temperature ranges, which are then particularly suitable for certain applications and components.
• the exact adjustment of the transformation temperatures is made with a sample taken during the melting process which allows an express control of the transformation temperatures for the liquid alloy.
• a sample for the express control it is preferable to use a cast wire drawn from the melt by means of a quartz tube in which a negative pressure is generated.
• the determination of the transformation temperatures can be carried out on this sample, depending on the expected application either in the casting state or after the heat treatment by known experimental methods for the detection of phase transitions.
• the transformation temperature on the sample may be by calorimetry, dilatometry, electrical conductivity measurement, light microscopy, or acoustic emission measurement.
• the martensitic transformation can also be initiated in a defined temperature range via externally applied voltages.
• the transformation temperatures in the material increase linearly with the load. This increase in the transformation temperatures must already be considered in the production of components made from the alloy according to the invention, if mechanical stresses are to be expected there.
• the damping maximum is also considerably influenced by the microstructure of the alloy, with larger grains leading to better damping properties.
• the grain size of the alloy can be adjusted so that for each specific application, an optimal compromise between the damping capacity and the mechanical properties is achieved.
• an improvement of the damping properties can be achieved by a heat treatment.
• a heat treatment As particularly effective has an annealing at temperatures of 650 0 C to 950 0 C followed by cooling or quenching (quenching) in liquid or gaseous media such. As air, liquid nitrogen, water, salt bath or oil proved.
• the temperature of the quenching medium should preferably be above the M s temperature in order to avoid uncontrollable shifts in the transformation temperatures in the material.
• the aging sensitivity of the transition temperatures can be reduced according to the invention by an additional aging of the quenched alloy at a temperature of 150 0 C to 250 0 C. Expediently, such outsourcing takes 5 to 120 minutes.
• a martensitic structure can be produced in the surface layer according to a further feature of the invention by laser remelting.
• the 5 edge layer takes over the damping roll, without the entire component having to undergo a cost-intensive heat treatment.
• the transformation temperatures of the alloy during melting by the express control are adjusted so that, taking into account the cooling conditions during laser remelting, the transformation temperatures in the surface layer correspond to the application temperature of the component.
• the alloys obtained by the process according to the invention can be used particularly advantageously for reducing vibrations for noise damping on mechanically loaded components, in particular in the case of
• Generator housings, vibrating machines, precision equipment, electronic
• Instruments, tools which are exposed to or produce vibrations and / or impacts during operation in particular stamps, dies,
• the sample is a cast wire having a length of 10 to 150 mm (preferably 15 to 100 mm) and a cross-sectional area of 0.2 to 7 mm 2 , preferably 0.7 to 3.2 mm 2 . This is pulled out of the melt with the help of a quartz tube, in which a negative pressure is generated. This sample can be used directly and very quickly with known detection methods. In a preferred method also used here, the acoustic emission is tracked over a temperature profile.
• Fig. 1 Formation of the specific damping capacity of the alloy of the example taken for a heating and cooling cycle
• FIG. 1 shows a measurement diagram which was taken for the example described above.
• the specific damping capacity is plotted in% above the temperature in ° C.
• the temperatures were run in a heating and cooling cycle from below zero to 200 0 C and back.
• the exemplary alloy in the austenitic interval much higher attenuation can be achieved than in the martensitic, so that the frequently occurring in the art restriction to martensitic structures must lead to significant disadvantages for the alloy properties.
• the example alloy reaches its maximum damping properties at a temperature of 120 0 C and thus successfully fulfills the task.
• the achievable damping is over 70%.

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• 2005
  • 2005-07-27 DE DE102005035709A patent/DE102005035709A1/de not_active Ceased
• 2006
  • 2006-07-27 JP JP2008523117A patent/JP2009503250A/ja not_active Withdrawn
  • 2006-07-27 DE DE112006002577T patent/DE112006002577A5/de not_active Withdrawn
  • 2006-07-27 US US11/995,842 patent/US20080298999A1/en not_active Abandoned
  • 2006-07-27 WO PCT/DE2006/001305 patent/WO2007012320A2/de active Application Filing
  • 2006-07-27 EP EP06775757A patent/EP1910582B1/de not_active Not-in-force

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