With the continual depletion of free-milling iron ores, the development of low-grade and fine-size refractory iron ores is of great significance.
随着我国易选铁矿石资源的日趋枯竭，开发利用贫、细难选铁矿资源具有十分重要的现实意义。
2
The experimental results have shown that the modern vibration-free face-milling cutter can not only reduce vibration and noise but also increase the surface finish quality and tool life.
试验结果表明，这种新型减振端铣刀不仅可以减少振动和噪声，而且还可以提高表面加工质量和刀具寿命。
3
Some small grain free regions (GFR) near the hole in the transmission electron microscopic specimen of this material prepared by ion milling was observed.