Fabrication Of Microscale Ordered-reinforced Composite And Its Mechanical Characterization

MEMS(Micro Electro-Mechanical Systems) has the furtherdevelopment under the need of technology and production, the appliedcircumstances of MEMS tiny devices are more and more complex,MEMS tiny devices have some new requirements to the materials whichmake of the MEMS tiny devices. No matter the MEMS traditional Si orother MEMS materials rising in recent years can not meet therequirements at the same time, so there is necessary to explore anddevelop new MEMS structure materials which are different with theexited MEMS materials in order to adapt the development of MEMSand fabrication and application of MEMStiny devices.The composite material whose performance can be designed maybe can solve the new problem, base on mature composite material theoryand existed experimental conditions, according to new materialrequirements of MEMS tiny devices.We propose the composite materialsolution,select the electroplated Ni wire which has the good mechanicalproperties as the reinforcement, select the acrylic polyurethane which hasthe stable chemical properties as matrix, the result of the ANSYSsimulation show that in the coated model, matrix can ease the stress concentration on the reinforcement well among the sandwichmodel,filling model and the coated model, in the same condition, coatedmodel composite material can bear bigger stress.the influence ofreinforcement integral shape to the properties of composite material isbigger than the volume content and the size of reinforcement.According to result of the simulation, design four coated compositematerials with the different shape of reinforcement,fabricate theelectroplated Ni wire whose integral shape is ordered-net through the thetypical micro-processing technology, complete the matrix coat onreinforcement through the electrophoresis technology,get the fiber-coatedcomposite material,hexagon-coated composite material,round-coatedcomposite material and quadrilateral-coated composite material.The result of micro-tensile show that the properties ofcomposite material have the different improvement after thecomposite.The tensile strength(σb),strain(ε) and Young's modulus(E) ofmatrix are 51.63MPa,4.024% and 1.528GPa;while theσb,εand E offiber-coated composite material are 125.04MPa,4.257% and 5.991GPa,are 2.42,1.06and 3.9 times of the matrix; theσb,εand E of thehexagon-coated composite material are 125.6MPa and 6.035GPa, are2.42 and 3.9 times of the matrix under theεfall 0.233%, respective; theσb,εand E of the round-coated composite material are 151.7MPa and5.289GPa, are 2.94 and3.46 times of the matrix under theεfall 0.728%; heσb,εand E of the quadrilateral-coated composite material are284.4MPa 3.518% and 5.289GPa, are 4.5 and3.468times of the matrixunder theεfall 0.506%. The stress-strain curve and SEM show that in thecoated composite, the matrix fractures earlier than the reinforcement, thenthe reinforcement will be stress concentration and plastic deformation ondifferent level before its fracture,composite material will fracturetoo,finally.