Fatigue Of Metals Copper Alloys - Indico
Fatigue of Metals Copper AlloysSamuli Heikkinen 26.6.2003
Temperature Profile of HDS Structure T 70 C
Stress Profile of HDS StructureStress amplitude 220 MPa
CLIC Number of Cyclesf 100 Hz24 hours / day30 days / month9 months / year20 years Total lifetime: 5*1010 Cycles
Fatigue Occurs when a material experiences lengthy periods of cyclic or repeated stresses Failure at stress levels much lower than under static loading Fatigue is estimated to be responsible for approximately 90% of all metallic failures Failure occurs rapidly and without warning There is no fixed ratio between materials Yield- and Fatigue Strength Normally the ratio varies between 30-60% Fatigue Strengths are usually average values
S-N CurveNormally data from the fatigue tests are plotted at S-N curve. Asstress S versus the logarithm of the number of cycles to failure, N.When the curve becomes horizontal, the specimen has reached itsfatigue (endurance) limit, ferrous and titanium alloys.This value is the maximum stress which can be appliedover an infinite number of cycles.The fatigue limit for steel is typically 35 to 60% of thetensile strength of the material.Fatigue strength is a term applied for nonferrous metals and alloys(Al, Cu, Mg) which do not have a fatigue limit.The fatigue strength is the stress level the material will failat after a specified number of cycles (e.g. 107 cycles). Inthese cases, the S-N curve does not flatten out.Fatigue life Nf, is the number of cycles that will cause failure at aconstant stress level.
Things that have an effect on fatigue strength Grain size Corrosion Frequency
Things that have an effect on fatigue strength Grain size Corrosion Frequency Vacuum
Things that have an effect on fatigue strength Grain size Corrosion Frequency Vacuum The Average Mean tressPulsating tensionstress
Things that have an effect on fatigue strength Grain size Corrosion Frequency Vacuum The Average Mean Stress Ductility (at small values of N) Surface finish (Notch effect) Microstructure (‘Notch effect’) Temperature (Strength decreases increasing the temperature. Exception confirms the rule )
Pure Copper Properties, annealed and cold workedAnnealedCold WorkedUltimate Tensile Strength [MPa]240380-415Yield Strength [MPa]70345-380Fatigue Strength at 108 cycles [MPA]75126Figure. S-N curves of pure copper, Annealedand Cold Worked.
How alloying elements affect the properties of copper Alloying can increase the strength, hardness, electrical and thermal conductivity, corrosion resistance orchange the color of a metal. The addition of a substance to improve one property may have unintended effects on other properties. The best way to increase the electrical and thermal conductivity of copper is to decrease the impurity levels.
Effect of temperature on the softening of copper alloys
Properties of some Copper Alloys(Outokumpu Poricopper Oy)CDAAcronymThermalConductivityat 20 C[W/(m*K)]Oxygen-free aringOxygen-free ough-Pitch hromiumC18200Cu-Cr1301-3432.3-2.0520-193Cadmium CopperC162003601.9247483205Cu Ni2533.534530140269Cu ro-NickelAluminum BronzeZirconium CopperC15000ElectricalResistivityat 20 C[µOhm*cm]Yield StrengthCold Worked84% 24 C [MPa]Yield StrengthAnnealed24 C [MPa]Fatigue StrengthCold WorkedNumber ofCycles[300x106]
Comparison of Potential Copper AlloysAlloy nameCu OFECu CrCu CdCu Zr T [ C] (HDS Structure)71888077σThermal (Thermal Stress of HDS Structure) [MPa]234305244263σFatigue (Fatigue Strength at 108 cycles) [MPa]11719320524121.581.191.09σThermal / σFatigue
Ultrasonic Fatigue TestingUIP250 Ultrasonic Processor 250 WattsFrequency: 24 kHz86*1062*1091.5*10105*1010Cycles / hourCycles / dayCycles / weekCycles / 3.5 weeks Make specimens from different materials. Adjust different stress levels. Create conditions as realistic as possible. (Vacuum etc.) Generate the S-N curves.
fatigue (endurance) limit, ferrous and titanium alloys. This value is the maximum stress which can be applied over an infinite number of cycles. The fatigue limit for steel is typically 35 to 60% of the tensile strength of the material. Fatigue strength. is a term applied for nonferrous metals and alloys (Al, Cu, Mg) which do not have a fatigue .
Heat-Resistant Alloy Castings 8, 9 Aluminum Alloys 9, 10 Aluminum Casting Alloys 10, 11 Copper Alloys 12, 13 Copper Casting Alloys 13, 14 Magnesium Alloys/ Casting Alloys 14 Magnesium Alloys/Wrought Alloys 15 Nickel Alloys 15 Super Alloys 16-18 Tin Alloys 18 Zinc Alloys 19 Precious Metal Alloys 19 Ni-Cr-Mo alloys 19
table 2 - selection of european standards for Product forms in copper and copper alloys Product form en no full standard title Plate, sheet, strip and circles 1652 Copper and copper alloys. Plate, sheet, strip and circles for general purposes Strip (springs and connectors) 1654 Copper and copper alloys. Strip for springs and connectors
Plate, sheet, strip and circles 1652 Copper and copper alloys. Plate, sheet, strip and circles for general purposes Strip (springs and connectors) 1654 Copper and copper alloys. Strip for springs and connectors Seamless tubes 12449 Copper and copper alloys. Seamless, round tubes for general purposes Seamless heat exchanger tube 12451 12452
36 copper tube (a) - high side copper 4a1846-01 1 1 1 1 37 copper tube (b) - high side copper 3a1317-01 1 1 1 1 38 copper tube (c) - high side copper 3a1316g01 1 1 1 1 39 copper tube (d) - high side copper 3a1311g01 1 1 1 1 40 heat exchanger copper 2a1498g01 1 1 1 1 41 strainer - 4a0397-01 1 1 1 1 42 copper tube (a) - hot gas copper 4a1878-01 1 .
Metals vs. Non-Metals; Dot Diagrams; Ions Metals versus Non-Metals Dot Diagrams Metals are on the left side. Non-metals on the right. Metals tend to lose electrons. Non-metals gain them tight. Dot Diagrams (sometimes known as Lewis dot diagrams) are a depiction of an atom’s valence elect
Abstract The fatigue performance of pure copper of the oxygen free, high conductivity (OFHC) grade and two copper alloys (CuCrZr and CuAl-25) was investigated. Mechanical testing and microstructural analysis were carried out to establish the fatigue life of these materials in the unirradiated and irradiated states.
ance, followed closely by arsenical copper. Phosphorus deoxidized copper, aluminum bronze and 95-5 copper nickel are somewhat better, followed by aluminum brass and 90-10 copper-nickel. Of the copper alloys, 80-20, 70-30 and 60-40 copper-nickel are the most corrosion resistant. Monel alloy 400 (7'½o Ni-Cu) has even higher
monitors, and flexible seating to accommodate small group, large group, and individual work. The classroom has a maximum capacity of 36 students. Figure 1 shows the classroom before and after redesign, and Figure 2 shows three views of the new ALC. Participants Faculty and students who had taught or taken at least one
