Research On Fe-16Cr-2.5Mo Alloy Mechanics And Damping Performance

The damping alloy can eliminate or reduce the vibration and noise and has functions of preventing fatigue failure,noise reduction and environmental protection,etc.It can also be used as a structural-functional integrated material by processed into mechanical components.In this paper,four kinds of Fe-16Cr-2.5Mo alloys were prepared by vacuum induction melting process.The mechanical properties and damping capicit y were tested after heat treatment at different temperatures?900°C,1000°C,1100°C?.The vibration damping properties of the four alloys were tested by bending resonance method.The micro-structure of the alloy was anal yzed and discussed by using metallographic microscope,scanning electron microscope,transmission electron microscope and other experimental instruments.The effects of alloying elements and heat treatment temperature on the mechanical properties and damping capacit y of the Fe-16Cr-2.5Mo alloy were studied.The results show that with the annealing temperature increasing to 1000°C,the strength of Fe-16Cr-2.5Mo alloy without alloying elements peaks.The maximum tensile strength is 471MPa,and the ma ximum yield strength is346.5MPa.With the increase of the annealing temperature,the plasticit y and toughness of the alloy graduall y decreased.The damping capacit y of the alloy has a peak at 1000°C as the heat treatment temperature rises.The maximum damp ing value Q^-1 is 9.5?10^-3.In the alloy,when the contents of Mn and Si increased by 0.3%and 0.5%,respectivel y,the grain of the alloy will coarsen,the strength will increase while the plasticit y will decrease.The maximum yield strength and tensile strength can be increased by 9.5%and 8.7%.The toughness of the alloy increased 9.1%at900°C and decreases 90.8%and 75.4%at 1000°C and 1100°C.The addition of0.5%Cu increases the strength and decreases the plasticity.The maximum yield strength and tensile strength can be increased by 5.4%and 2.8%.The toughness decreases 28.2%at 900°C and increases 234.7%and 224.1%at 1000°C and1100°C.Adding 0.8%Ni and 0.1%Nb,it will make grain refined.At the same time it can increase strength,ductilit y and toughne ss.The maximum yield strength and tensile strength can be increased by 8.0%and 5.2%.The toughness increases4.4%,34.8%and 6.9%at 900°C¹100°C.Compared with Fe-16Cr-2.5Mo alloys without other alloyi ng elements,adding 0.3%Mn and 0.5%Si,the alloy damping capacit y decreases 10.6%and 16.8%at 900°C and 1000°C,while,it increases 8.1%at 1100°C.At 900°C,there is little change in damping capacit y when adding 0.5%Cu.But the damping capacit y of the alloy is reduced 18.9%and 13.8%at 1000°C and 1100°C.At 900°C,there is little change in damping capacit y when adding 0.8Ni and 0.1%Nb.But the damping capacit y of the alloy is reduced 40.5%and 63.8%at 1000°C and 1100°C.And the alloy with 0.8%Ni and0.1%Nb deteriorates seriousl y compared with the alloy with0.5%Cu.The Fe-16Cr-2.5Mo alloy with no other elements added had the best overall performance at 1000°C.The addition of alloying elements reduces the damping capacit y of the alloy while increasing the strength of the alloy.The addition of0.8%Ni and 0.1%Nb can significantl y refine the grains and increase the toughness.Therefore,appropriate adjustments can be made to alloying elements for different applications and perfor mance needs.