S型B_4C-SiC/C功能梯度材料的设计和制备

Design and Fabrication of S-Type B_4C-SiC/C Functionally Graded Materials

对（ｌ－×）（８０％Ｂ４ＣＣ－２０％ＳｉＣ）／ｘ Ｃ（体积分数）功能梯度材料的 ×＝０． ２， ０．４， ０．６， ０．８的各层 分别在２０００℃，２０ＭＰａ进行了热压，测定了各层的密度，线膨胀系数，弹性模量和抗弯强度等． 按线性成分分布函数的６层和１１层梯度材料热压后都出现了裂纹．采用了不同于幂函数的Ｓ 型成分分布函数设计，热压了１１层（×＝０．２～１．０）的功能梯度材料，其抗弯强度为２１６ＭＰａ，抗热震 性＞５００℃．

The x=0.2,0.4,0.6,80 layers of (l -x) (80%B4C-20%SiC) /xC (volume fraction) Functionally Graded Materials were hot-pressed respectively. The density, linear thermal expansion, elastic modulus and flexural strength were tested. There are crackles in FGMs of 6 and 11 layers that are designed by linear function. The S-type function of compositional distribution as a designed method applied to investigate FGM. As a result the flexural strength is 216 MPa and thermal shock resistance A,, >500C for 11 layers (x= 0.2~l) FGMs of S-type.