摘要
用XRD分析了YT14硬质合金在常规烧结态和不同淬火温度的热处理态下粘结相的相组成以及WC相和(Ti,W)C固溶体相的微观应力,用EDX技术测定了Co粘结相成份,用TEM大量观察了合金的显微结构。结果表明,淬火处理使W、Ti原于在粘结相中的平均浓度增加,从而改善了粘结相的相组成;部分结晶较完整又有较大尺寸的WC晶粒边缘出现滑移台阶,降低了WC晶粒间的邻接度,减少了粘结相的平均自由程;回火处理降低了WC相和(Ti,W)C相的微观应力,使合金的性能进一步提高。
An analysis has been made of the binder phase component and the micro-stress in WC
and(Ti,W)C phases of YT14 cemented carbides on conventional sintering and heat-treat-
ment in different quench temperatures by X-ray difffaction.The binder phase composition of
the specimens has been determined by EDX.Many observations of microstucture of speci-
mens were carried out with TEM.It is showed that the concentrations of W and Ti atoms in
binder phase were increased,and the binder phase component was improved by quenching.
There were slip steps on WC grains boundary of crystallized perfection and the larger size af-
ter heat-treatment,which reduced the contiguity of WC grains and the mean free-path in
binder phase.Total micro-stress in WC and(Ti,W)C phase was decreased by temper,
which ensured better properties of the YT14 alloy.
基金
国家计委"八五"攻关项目
关键词
硬质合金
热处理
显微结构
性能
cemented carbides
heat-treatment
TEM
X-ray diffraction
binder phase
slip step
