Experiment And Finite Element Analysis On Micro Hot Embossing Process Of Zr-based Amorphous Alloy

In the field of micro-manufacturing, micro hot pressing technology is widely usedbecause of the simple process, low cost and can achieve a smaller size. The choice of moldmaterial is a very important part of micro hot pressing technology. Amorphous alloy isvery suitable for micro hot embossing mold material due to the excellent mechanical andphysical and chemical properties. In this paper, the Zr₆₅Cu_17.5Al_7.5Ni₁₀bulk metallic glassis chose as the study object. By using a self-designed micro-hot pressing mold,experiments of micro hot pressing are carried out on the Zwick electronic materials testingmachine, effect of temperature, extrusion rate and other process parameters on micro hotpressing is studied, experimental results are studied with theoretical analysis and theprocess of micro hot pressing is simulated by using the Deform-3D finite elementsimulation software.The copper mold casting method was used to produce Zr₆₅Cu_17.5Al_7.5Ni₁₀bulkmetallic glass. The structure and thermal properties of the sample were analyzed by usingX-ray diffraction （XRD） and differential scanning calorimetry （DSC） methods. Itssupercooled liquid region was determined to be377℃⁴77℃.H13steel is chose as the mold material. To consider the size factor, positioningrequirements and needs to take place, the micro hot pressing mold is designed by UGSNX6.0software. The mold structure is simple, easy removal and also relatively easy formanufacture.By selecting different temperature, extrusion speed, maximum load, dwell time,micro-groove and other process parameters, repeated cross-over experiments are carriedout on the Zwick electronic materials testing machine. The results show that temperatureof430℃, extrusion rate of5μm/s, maximum load3000N, the holding time120s is anice combination of process parameters. Also found that micro-hot pressing is related withthe size of the micro-groove. As the width decreases, a significant reduction in thepercentage of filled.Theoretical analysis of the hot pressing on bulk metallic glass is done by the use ofPoiseuille formula. Analysis showed that: in the uniform filling of the hypothesis, the use of Poiseuille equation can well fit the experimental results. That is to say the Poiseuille’slaw that will promote the use of micro-hot in the amorphous alloy is feasible. Meanwhile,t appropriate deformation of he Poiseuille formula can be used to estimate themicro-groove filled full time required of the bulk metallic glass.Based on Deform-3D finite element software, the micro-hot-pressing process of thebulk metallic glass in the supercooled liquid region was simulated. It show that thesimulated stress-strain curve is really fit better within the experimental and theoreticalcurves for the strain in the range of0.4, which illustrates the simulation results are withsome reference.