The Study On Cu-Al Alloys Damping Capacity

We have designed four kinds of alloys of different composition in comparison based on deeply understanding the mechanism of Cu-Al alloy's high damping capacity.The impact on its martensite structure,Ms,damping capacity and mechanical property made by the composition and heat treatment process were analized by means of thermal dilatometer,x-ray diffraction,damping detection,SEM,OM.The results indicate that:(1) Mn has relatively great impact on the alloy's damping capacity.it can extend to B phase district in favor the birth of Thermo-elasticity martensite.Damping capacity was considerably improved after adding RE because the interface of martensite increase and the pinning of defects and vacancise decline.The strength,yield strength and ductility of the alloy were improved owing to the co-work of Mn and RE.(2) The Cu-11Al-5Mn-Re(wt%)alloy we got is nearly eutectoid.It has a high Ms temperature,good damping capacity and mechanism as well as anti-marsentise decomposition capacity.(3) When Cu-11Al-5Mn-Re(wt%)alloy was aging at 200℃,its damping and mechanism properties reached to satisfying level.Its Q-1is 9.776×10-2, Ms is 90℃and ultimate strength is 579.89Mpa.The method of the marsentise was improved during the aging and the coordination became better under the external force.When aging at 400℃,there wereγ2 coming into being.But certain amount marsentise remained in the alloy which indicated its resistence to aging at moderate temperature.