Semi-Solid Near-Net Forming of Eco Functionally Graded Material with Low Load on Environment

本文对铝基生态功能梯度材料的低环境载荷近净成形进行了研究。功能梯度材料是一类具有连续材料组成变化的复合材料。已经发现FGM具有良好的耐热负荷和耐磨性。为了经济地制备功能梯度材料，福井等人提出并发展了一种离心分离技术。根据其温度确定，并且SiC（固相）颗粒被建模为刚性颗粒。液相（铝熔体）的流动被假定为由以下方程控制。在目前的二维SPH模拟中，SiC颗粒以显式的方式被放置在模型中。分布的颗粒在尺寸上比实际SiC颗粒大得多。然而，这些尺寸比凸模和凹模之间的间隙小得多。因此，我们认为SPH模型中的颗粒足够小，可以代表SiC颗粒。每个SiC颗粒由12个SPH颗粒组成，如图1所示。总共有782351个SPH颗粒，即，1951和401 SPH粒子分别放置在水平和垂直方向上。忽略SiC体积分数的波动，并且将SiC和富铝区域中的SiC体积分数分别设定为30%和0%。

In present research, an investigation is being carried out on the near net shape forming of Al-base eco- functionally graded material (FGM) with low load on environment. FGMs are a class of composite materials that have continuous material composition changes. FGMs have been found to have good resistances to thermal loadings and wear. In order to produce the FGMs economically, Fukui and his colleagues proposed and have developed a centrifugal technique.In present SPH analyses, the aluminum melt is approximated by an incompressible fluid whose viscosity. is determined according to its temperature and SiC (solid phase) particles are modeled as rigid particles. The flow of liquid phase (aluminum melt) is assumed to be governed by the following equations.In present two-dimensional SPH simulation SiC particles are placed in the model in an explicit manner. The distributed particles are much larger than the actual SiC particles in their sizes. However, the sizes are much smaller than that of gap between the punch and the die. Therefore, we think that the particles in the SPH model are small enough to represent the SiC particles. Each SiC particle consists of 12 SPH particles as illustrated in Figure 1. There are a total of 782351 SPH particles, i.e., 1951 and 401 SPH particles are placed in the horizontal and the vertical directions, respectively. The fluctuations in the volume fraction of SiC were ignored and the volume fractions of SiC in SiC and aluminum rich regions were set to be 30 % and 0 %, respectively.