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

本文对低环境负荷的铝基生态功能梯度材料(FGM)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。功能梯度材料已被发现具有良好的耐热负荷和耐磨性。为了经济地生产功能梯度材料，Fukui和他的同事们提出并开发了一种离心法。在目前的SPH分析中，铝熔体近似为不可压缩流体，其粘度。是由其温度决定的，而碳化硅(固相)颗粒被模拟为刚性颗粒。假设液态(铝熔体)的流动符合以下方程。在目前的模型中，二维SPH模拟的碳化硅颗粒以显式的方式被放置在模型中。分布的颗粒比实际的颗粒尺寸大得多。然而，这些尺寸远远小于凸模和模具之间的间隙。因此，我们认为SPH模型中的粒子足够小，足以表示碳化硅粒子。如图1所示，每个碳化硅颗粒由12个SPH颗粒组成。共有782351个SPH颗粒，即1951年和401个SPH颗粒分别放置在水平和垂直方向。忽略了碳化硅体积分数的波动，将碳化硅和富铝区的碳化硅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.