ZrC改性石墨对低碳Al_(2)O_(3)-C耐火材料结构与性能的影响

Effect of ZrC modified graphite on microstructure and properties of low-carbon Al_(2)O_(3)-C refractories

为解决目前低碳Al_(2)O_(3)-C耐火材料性能下降、寿命缩短等问题,以Zr粉和鳞片石墨为原料,以NaCl和NaF为熔盐介质,在氩气气氛中于1000℃保温3 h合成了ZrC改性石墨。然后以电熔白刚玉、α-Al_(2)O_(3)粉、Al粉、Si粉、鳞片石墨和ZrC改性石墨为原料,以酚醛树脂为结合剂制备了低碳Al_(2)O_(3)-C耐火材料试样。研究了ZrC改性石墨添加量(加入质量分数分别为0、1%、3%、5%)对低碳Al_(2)O_(3)-C耐火材料的物相组成、显微形貌、物理性能的影响。结果表明:与仅添加鳞片石墨的试样相比,引入1%~3%(w)的ZrC改性石墨可显著提高低碳Al_(2)O_(3)-C耐火材料试样的力学性能,但是当引入5%(w)的ZrC改性石墨时,降低了其性能。添加3%(w)ZrC改性石墨时,试样的力学性能最优,其常温抗折强度和常温耐压强度分别为22.3和97.5 MPa。

In order to solve the problems of performance deterioration and short life of low-carbon Al_(2)O_(3)-C refractories,ZrC modified graphite was synthesized in argon atmosphere at 1000℃for 3 h using Zr powder and flake graphite as raw materials,NaCl and NaF as the molten salt medium.Then,low-carbon Al_(2)O_(3)-C refractory samples were prepared using white fused corundum,α-Al_(2)O_(3)powder,Al powder,Si powder,flake graphite and ZrC modified graphite as raw materials,and phenolic resin as the binder.Effects of the ZrC modified graphite addition(0,1%,3%,and 5%,by mass)on the phase composition,microstructure and physical properties of the low carbon Al_(2)O_(3)-C refractories were studied.The results show that the introduction of 1%-3%ZrC modified graphite can significantly improve the mechanical properties of the low carbon Al_(2)O_(3)-C refractory samples compared with samples with only flake graphite.However,5%ZrC modified graphite deteriorates the properties.The sample with 3%ZrC modified graphite has the best mechanical properties,22.3 MPa of cold modulus of rupture and 97.5 MPa of cold crushing strength.