CAJ | 학술논문

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。
이초중력보조연소합성용삼공예제비료구유제도특정적 WC-Ni 경질합금재료。해공예이려열반응위기출，시가보조초중력장，제비출구유제도특정적경질합금재료。해재료구유쌍층제도결구：연중력장방향의차위Ni금속층화 WC-Ni경질합금층。기중Ni금속층적경도치위72HRA；경질합금층적경도치최고위87HRA。Ni용체재용삼과정중적교동사 WC재Ni금속층출현미산분포병도치경질합금층 WC 적장대。용체유저층개시향정층축점응고적특점사해제도재료항만강도강저。
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 di-rection,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.