摘要
本研究通过SEM、EBSD等表征手段分析了0、0.5%(质量分数,下同)、1%的Cr含量对WC-10%Co亚微晶硬质合金中WC/WC晶界分布的影响。结果表明,不同Cr含量的合金中,都出现了占比较高的∑1、∑2、∑4、∑13 CSL晶界;随Cr含量增加,WC/WC晶界总长度增加,小角度晶界与大角度晶界占比没有明显变化;∑1和∑13晶界占比没有明显的规律性变化,可能与Cr的晶界偏聚不直接影响∑1和∑13晶界的形成有关;∑2晶界占比升高,∑4晶界占比减小,这可能是因为Cr在非∑2扭转晶界的偏聚一方面抑制了WC晶粒生长,保留了其多面特征,促进了烧结时的晶粒重排形成更多∑2晶界;另一方面,Cr含量增加,更强地抑制了WC其他方向的生长,而原始的∑2扭转晶界不受影响,在烧结驱动力的作用下晶粒合并长大,继承自研磨态晶粒团簇的∑4晶界也随着减少。Cr含量进一步增加对∑2、∑4晶界分布影响的幅度减小,则可能是因为Cr在WC/WC晶界的偏聚渐趋饱和。
In this study, the effect of different Cr contents including 0, 0.5%, and 1%(mass fraction) on the distribution of WC/WC grain boundaries in WC-10%Co submicron cemented carbide was investigated by SEM, EBSD, and other methods. The results indicate that ∑1, ∑2, ∑4, and ∑13 CSL boundaries with a high proportion are formed in cemented carbides with different Cr contents. As Cr content increases, the total length of WC/WC grain boundaries improves, while the proportion of low-angle and high-angle grain boundaries has a slight change. The proportion of ∑ 1 and ∑ 13 grain boundaries changes without apparent law, which may be related to the fact that the Cr segregation at grain boundaries does not directly affect the formation of ∑ 1 and ∑ 13 grain boundaries. In addition, as the proportion of ∑ 2 grain boundaries increases, that of ∑4 grain boundaries decreases. On the one hand, this could be explained by the fact that the segregation of Cr at boundaries except ∑ 2 twist boundaries has restrained the growth of WC grains, retained their multifaceted characteristics, and promoted the formation of ∑ 2 grain boundaries through grain rearrangement during sintering. On the other hand, as Cr content increases, the growth of WC grains in other directions has been inhibited significantly, and the original ∑2 twist boundaries are not affected. Under the driving force of sintering, grains begin to merge and develop, and ∑4grain boundaries with as-milled grain clusters decrease. Furthermore, the increase in Cr content has a slight influence on the distribution of ∑2 and ∑4 grain boundaries, which may be caused by the gradual saturation of Cr segregation at the WC/WC grain boundaries.
作者
左锐
陈飞
李丽
Zuo Rui;Chen Fei;Li Li(Zhuzhou Huarui Precision Cutting Tools Co.,Ltd.,Zhuzhou Hunan 412000,China)
出处
《硬质合金》
CAS
2022年第6期439-445,共7页
Cemented Carbides
关键词
硬质合金
铬
CSL晶界
特征晶界分布
cemented carbide
Cr
CSL grain boundaries
distribution of specific grain boundaries
