摘要
The micro gear mold for powder injection molding was made by electroforming process of Fe-Ni and Fe-Ni-W alloys using UV-lithography process. Kinetics and activation energies in electroplating of both alloys were investigated to determine the best process conditions. Fe content within electrodeposited Fe-Ni alloys increased with the increase of rotating disk speed and the decrease of temperature and it is considered from the calculated activation energy of iron content that the rate determining step is controlled by mass transfer. Iron content in Fe-Ni electrodeposit varied from 58.33% to 70.45% by increasing current density from 2 to 6 A/drn2. Also, iron content in Fe-Ni-W electrodeposit increased from 59.32% to 70.15%, nickel content decreased from 27.86% to 17.07% and the content of tungsten was almost consistent in the range of 12.78%-12.82% although the current density increases from 1.5 to 5 A/dm^2. For the electroforming of micro gear mold, SU-8 mandrel with 550 μm in diameter and 400 μm in height was prepared by UV-lithography processing. Subsequently, Fe-36Ni and Fe-20Ni-13W alloys micro gear molds were electroformed successfully. Surface hardness values of the electroformed micro molds were measured to be HV490 and HV645, respectively.
采用紫外线光刻工艺,将FeNi和FeNiW合金电铸成粉末注射成型用微型齿轮模具。研究电镀过程中2种合金的动力学和活化能,以确定最佳的工艺条件。电沉积FeNi合金中的Fe含量随着转盘速度的加快和温度的降低而增加,从计算得到的Fe组份活化能可以看出,速率控制步骤是传质。在FeNi电沉积物中,随着电流密度由2A/dm^2增加到6A/dm2,Fe含量从58.33%增加到70.45%。在电流密度从1.5A/dm^2增加到5A/dm^2的过程中,FeNiW沉积物中Fe含量从59.32%增加到70.15%,而Ni含量从27.86%下降到17.07%,但W的含量保持在12.78%－12.82%的范围。通过电铸,采用紫外线光刻工艺制备了直径550μm、高度400μm用于微型齿轮模具的SU8芯棒。随后,成功电铸成形了Fe36Ni和Fe20Ni13W合金微型齿轮模具,其表面硬度分别为HV490和HV645。
