Preparation of Fuctinally Graded Materials in high Energy Field of Plasma

功能梯度材料（FGM）是一种新概念的材料，是金属陶瓷、金属-聚合物、陶瓷-聚合物复合而成。由于陶瓷粉末、金属粉末和聚合物粉末的烧结温度不同，制备功能梯度材料的一般方法还没有建立。放电等离子烧结设备（SPS）是一种热压机。将粉末放入石墨模具中，并设置在SPS设备中。石墨模具由直流脉冲电流加热。脉冲电流在石墨模具中的粉末周围产生等离子体。新的模具，新的模具，其直径是不同的上部和下部之间，已经制成。这种模具导致梯度温度，并使其能够制备各种FGM。1.聚酰亚胺/金属（铝和铜）FGM：聚酰亚胺是一种优良的耐热聚合物。该聚合物用于IC封装和基底。聚合物和金属（Al和Cu）的组合提供了一侧是绝缘体的材料 ...更多信息 而另一侧是导电的。采用放电等离子烧结法可以得到致密的聚酰亚胺/Al或Cu功能梯度材料。2.ZrO_2（3Y）/金属（Ni和不锈钢）功能梯度材料：陶瓷材料具有脆性、耐热、抗氧化等特点。金属是可延展的，但它们在高温下熔化并氧化。陶瓷和金属的结合提供了一种良好的耐热材料，可以在高温下在空气中使用。采用放电等离子烧结法制备了致密ZrO_2（3Y）/金属（Ni和不锈钢）陶瓷。通过10层ZrO_2（3Y）与金属不同比例的梯度层，使残余应力得到松弛。3.功能梯度材料中的残余应力：残余应力来源于聚合物、金属和陶瓷的热膨胀失配。功能梯度材料的概念是指不同粉末配比的梯度层能够松弛残余应力。聚酰亚胺/金属功能梯度材料的残余应力通过聚合物和金属的塑性变形而得到松弛。陶瓷和金属的组合不能提供足够的弛豫。这就是为什么陶瓷层和金属层之间需要十层的原因。高压放电等离子体烧结装置：等离子体在石墨模具中的粉末周围产生。针对放电等离子烧结设备能量较低，不足以制备高性能功能梯度材料的问题，研制了一种可在高压条件下使用的放电等离子烧结设备，以提高等离子体的能量。这对于FGM的形成是有效的。少

Functionally graded materials (FGM) are new concept of materials, and formed by the combination of metalceramics, metal-polymer and ceramics-polymer. General methods of the preperation of FGM has not been established, bacause the sintering temperature of ceramic, metal and polymer powders is different. A spark plasma sintering equipment (SPS) is a sort of a hot-press. Powders are put in a graphite die, and set in the SPS equipment. The graphite die is heated by direct pulse current. The pulse current generates plasma around powders in the graphite die. New die, New die, of which diameter is different between an upper part and a lower part, has been made. This die leads to graded temperatures and makes it possible to prepare various kinds of FGM.1.Polyimide/metal (Al and Cu) FGM : The polyimide is a excellent heat-resisting polymer. This polymer is used for an IC package and base. The combination of the polymer and metals (Al and Cu) offers the material of which one side is an insulator … More and other side is conductive. The dense polyimide/Al or Cu FGM can be obtained by spark plasma sintering. Residual stress is relaxd by the three graded layrs of the different ratio of polyimide and the metal.2.ZrO_2(3Y)/metals (Ni and stainless steel) FGM : Ceramic materials are brittle, heat-resisting and oxidation-resisting. Matals are ductile, but they melt and are oxidized at high temperatures. The combination of the ceramics and metals give a good heat-resisting material that can be used in air at high temperature. The dense ZrO_2 (3Y)/metals (Ni and stainless steel) were prepared using the spark plasma sintering equipment. The residual stress is relaxd by ten graded layrs of the different ratio of ZrO_2 (3Y) and the metal.3.Residual stress in FGM : The residual stress comes from the mismatch of the thermal expansion of the polymer, metal and the ceramics. The concept of FGM is the fact that the graded layrs of the different ratio of powders can relax the residual stress. The reasidual strss of the polyimide/metal FGM is relaxd by the plastic deformation of polymers and metals. The combination of ceramics and metals can not afford enough relaxation. That is why the ten layrs are needed between the ceramic and metal layrs.4. High voltage spark plasma sintering apparatus : Plasma is generated around powders in the graphite die. The energy of the spark plasma sintering equipment is low and not enough to create high performing FGM.The apparatus that could be used under the condition of high voltage was made to increase the energy of the plasma. This is effective for the FGM formation. Less