凝胶离心成形制备TiC-FeCrMo硬质合金  

CENTRIFUGAL GEL FORMING OF TIC-FeCrMo STEEL-BONDED CARBIDE

作　　者：石永亮[1] 郭志猛[2] 李秀敏[1] 

机构地区：[1]河北工业职业技术学院材料工程系,石家庄050091 [2]北京科技大学新材料技术研究院,北京100083

出　　处：《粉末冶金工业》2014年第1期26-31,共6页Powder Metallurgy Industry

基　　金：国家自然科学基金委员会资助(No.50774010);广东省教育部产学研结合项目(2011A090200091)

摘　　要：将凝胶离心成形工艺应用于TiC-FeCrMo硬质合金的坯体成形,研究了固含量对TiC-FeCrMo复合粉末浆料的流变性的影响,分析了凝胶离心成形过程中压力和聚合速率的关系,并研究了离心转速对坯体和烧结体性能的影响。结果证明:HEMA凝胶体系对TiCFeCrMo复合粉末具有很好的分散性,以油酸作分散剂,制备稳定且流动性好的浆料的最佳固含量为55%(体积分数),凝胶离心成形过程中压力能够加速浆料的固化,采用自行设计的离心成形机,选择最佳转速2 000r/min,制备出大尺寸棒状钢结合金坯体,坯体密度高、无残留气孔,强度高达30MPa,密度为4.07g/cm3,坯体经过真空脱胶烧结一体化烧结,1 420℃保温1h制备出钢结硬质合金烧结体,其密度为6.52g/cm3,抗弯强度1 580MPa。Centrifugal gel forming was employed to form the TiC-FeCrMo Steel bonded carbide green body.The effect of the solids loading on the rheological behavior of TiC-FeCrMo composite powders slurry was investigated.The relationship between pressure and polymerization rate was analyzed.Moreover,the influence of the rotation speed on the green and sintered bodies was also studied.As the result,the TiC-FeCrMo composite powders have a good dispersibility in the HEMA gel system.By using oleic acid as dispersion,the optimum solid loading to prepare the slurry with good flowability and good stability was 55vo1％.Pressure accelerated the solidification of the slurry during the centrifugal gel forming process.The large-scale clubbed green body with high density and no residue stomata was prepared by using an in-house made centrifugal forming device with the optimum rotation speed 2 000 r/min,the corresponding strength and density was 30 MPa and 4.07 g/cm3,respectively.After 1 h sintering at 1 420 ℃ in vacuum,the resulted transverse rupture strength and density achieved 1580 MPa and 6.52 g/cm3,respectively.

关 键 词：凝胶离心成形 钢结硬质合金 压力 自由基聚合 

分 类 号：TF124.3[冶金工程—粉末冶金]