Research On The Preparation Of Conductive Damping Composite Material And Its Application In Damping Steel Plates

Damping steel plate with constrained damping structure has been widely used toreduce noise of vehicle. It also can effectively consume energy from mechanicalvibration, resulting in vibration and noise reduction. Since the viscoelastic dampingmaterials in sandwich has characteristics of insulation and non-conductive, so there isno closed circuit during the welding process. It is important to make viscoelasticcomposite conductive materials of high conductivity and low filling volume to achievedamping steel plate multi-function.In this paper, firstly, the surfactant to modify the property of conductive graphitewas selected. Two phase conductive damping composite material was made by in-situpolymerization method with conductive graphite modified as filler and viscoelasticdamping materials as substrate. The dispersion of conductive graphite modified wasobserved to gain information through macroscopic deposition and microscopic lightmicroscopy. The mechanical properties, DMA, SEM and FTIR of conductive dampingmaterials were studied. Secondly, the influence of three process parameters on theperformance of the electrical and mechanical of conductive damping steel plate wasstudied. The influence of process parameters on the electrical conductivity was studiedby orthogonal experimental method. Finally, the influence of three process parameterson the damping performance of conductivity damping steel plates was studied. Theeffect of three process parameters on damping properties was studied by orthogonalexperimental method. The main research conclusions are as follows:(1) Dispersion of conductive graphite was improved greatly by mixing surfactants.The performance of dispersion effect is best when the ratio of PVP/conductive graphiteis25%, the ratio of CTAB/conductive graphite is5%and the ratio of SDBS/conductivegraphite is30%. Especially, the performance of dispersion effect is best of all when theratio of PVP/conductive graphite is25%. They can keep maintain60h, and the stabilityis better. So PVP/conductive graphite ratio at25%was choosed to modify theviscoelastic damping material.(2) The mechanical properties of the conductive damping composite material is effectively improved by conductive graphite. when conductive graphite content is7wt%,the tensile strength, elongation at break and tear strength achieved maximum were12.03MPa,442.83%and48.21kN.m-1, respectively. The dispersion of conductivegraphite is better by SEM when conductive graphite is7wt%. When the conductivegraphite content is too high or too low, it is not beneficial to dispersion in matrix ofviscoelastic damping material. FTIR shows that functional group changes of conductivegraphite did not happen and just change the surface adsorption ability of conductivegraphite. Thus it can effectively improve the performance of the conductive dampingcomposite material. It shows by DMA that the storage modulus and loss modulus ofcomposite material increase effectively by adding conductive graphite. With thetemperature increasing, the storage modulus of the viscoelastic damping materials andconductive damping composite material decrease, and the loss factor increases firstlyand then decreases at the same frequency.(3) Preparation process has greater impact on the electrical conductivity andmechanics performance of conductive damping steel plate. The logarithm of volumeresistivity about conductive damping steel plates modified or unmodified achieves theminimum of3.3and6.8, respectively. when conductive graphite content is7wt%,blending time is5min and mixing speed is100r/min; Shear strength and peel strengthtake the maximum of1.36MPa,1.32MPa,37.66N/cm and35.8N/cm, respectively.Preparation process parameter has much effect on the conductivity of conductivedamping steel plates, and little effect on mechanical. The size of the influence ofconducting parameter on conductive performance in the order followed by conductivegraphite content＞blending time＞mixing speed. The best preparation technologyparameters can be obtained through the orthogonal test. The conductive performance isbest when conductive graphite content is7wt%, blending time is5min and mixingspeed is50r/min.(4) Damping property of conductive damping steel plates was influenced bypreparation process in a way. The composite loss factor of conductive damping steelplates modified and unmodified achieves the maximum0.1964and0.1802respectivelyand vibration acceleration level takes minimum52.05dB and54.51dB respectively, when the graphite content is7wt%, blending time is5min and the mixing speed is100r/min. At this time the damping properties is better. The size of the influence ofconducting parameter on damping performance in the order followed by mixing speed＞conductive graphite content＞blending time. The best preparation technologyparameters can be obtained through the orthogonal test. conductive The dampingperformance is best when graphite content is7wt%, blending time is5min and mixingspeed is200r/min.In conclusion, it will provide reference value for the best preparation technologyparameters of conductive damping composites, and provide data support for theresearch on properties of conductive damping steel plates through the preparation ofconductive damping composite material, and its application research in damping steelplates.