超重力辅助燃烧合成熔渗梯度Ni-(WC-Ni)硬质合金复合材料  

Fabrication of gradient WC-Ni cemented carbide materials by high gravity-assisted combustion synthesis and infiltration

作　　者：杨增朝[1] 刘光华[2] 徐利华[1] 郭世斌[2] 李江涛[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中国科学院理化技术研究所,功能陶瓷材料研究组,北京100190

出　　处：《功能材料》2013年第18期2710-2714,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51002163,50932006);北京市自然科学基金资助项目(2112043)

摘　　要：以超重力辅助燃烧合成熔渗工艺制备了具有梯度特征的WC-Ni硬质合金材料。该工艺以铝热反应为基础,施加辅助超重力场,制备出具有梯度特征的硬质合金材料。该材料具有双层梯度结构:沿重力场方向依次为Ni金属层和WC-Ni硬质合金层。其中Ni金属层的硬度值为72HRA;硬质合金层的硬度值最高为87HRA。Ni熔体在熔渗过程中的搅动使WC在Ni金属层出现弥散分布并导致硬质合金层WC的长大。熔体由底层开始向顶层逐渐凝固的特点使该梯度材料抗弯强度降低。Gradient WC Ni cemented carbide materials were prepared by high-gravity-assisted combustion syn thesis and infiltration, where Ni melt was in situ synthesized and then infiltrated into porous compacts of WC powder. The obtained materials consisted of two layers and showed a gradient feature along the high-gravity direction, in which the upper layer was Ni metal and the under layer was WC Ni cemented carbide. The hardness of the Ni metal and WC-Ni cemented carbide reached 72 HRA and 87 HRA, respectively. The agitation of Ni melt during infiltration resulted in the presence of WC particles in the Ni metal and growth of WC grains in the cemented carbide layer. The WC-Ni cemented carbide materials showed a relatively low bending strength of 770 MPa, which may be connected with the down-to-up solidification kinetics.

关 键 词：超重力 燃烧合成 熔渗 梯度Ni-（WC—Ni）硬质合金 

分 类 号：TB333[一般工业技术—材料科学与工程]