摘要
材料致密度的高低和晶粒的大小直接影响材料的力学性能和使用性能。为了进一步提高WC-Al2O3复合材料的致密度和控制晶粒尺寸,利用改进的普通热压烧结工艺,即二阶段热压烧结工艺对WC-Al2O3复合材料进行烧结,研究确定最佳二阶段烧结工艺及其对复合材料微观组织和力学性能的影响。结果表明,WC-Al2O3复合材料的最佳二阶段热压烧结工艺为TSS3,即T1=1 600℃,T2=1 450℃,t2=6 h。在TSS3烧结制度下制备的WC-Al2O3复合材料,其致密度(TD)为99%,WC晶粒尺寸为2.38μm,维氏硬度为19.71 GPa,断裂韧性为12 MPa·m1/2,抗弯强度为1 285.03 MPa。与普通热压烧结制度下制备试样的力学性能相比,晶粒尺寸有所减小,致密度、硬度、断裂韧性和抗弯强度均有较明显提高。
Relative density and grain size could directly affect the mechanical properties and serve performance of WC - Al2O3 composites. To improve relative density and inhibit grain growth, the improved conventional hot pressing process, that is, the two step sintering process was used to consolidated WC -Al2O3 composites. The optimum two step sintering process and its effect on the microstructure and mechanical properties of WC -Al2O3 composites were investigated. The results showed that, when the WC -Al2O3 powders were hot pressed under the optimum two step sintering process （ TSS3 regime, T1 = 1 600 ℃, T2 = 1 450℃, t2 = 6 h）, a relative density of 99% and a grain size of 2. 38 μm were obtained, and an excellent Vickers hardness of 19. 71 GPa was achieved, combining a fracture toughness of 12 MPa · m1/2 with an acceptable flexural strength of 1 285.03 MPa. Compared with samples consolidated under conventional sintering regime, the grain size decreased, the relative density, Vickers hardness, fracture toughness and the flexural strength were all improved.
出处
《宝钢技术》
CAS
2014年第4期41-46,共6页
Baosteel Technology
