退火温度对微合金铁粉压缩性的影响

Influence of Annealing Temperature on Compressibility of Micro-alloyed Iron Powder

通过还原-磨选法制取的特种天然微合金铁粉具有优异的性能。为了提高铁粉的压缩性,研究了不同退火温度对微合金铁粉压缩性的影响。采用扫描电镜、X射线衍射和硬度测试,探讨了晶粒大小、显微硬度对微合金铁粉压缩性的影响。结果表明:不同温度退火后粉末形貌、松装密度和流动性变化不大;但退火温度对微合金铁粉的晶粒尺寸、显微硬度影响较大,进而影响压缩性。随着退火温度的升高,粉末的晶粒尺寸增大,显微硬度降低。粉末的压缩性随着晶粒尺寸的增加有所提升;同等压力下压缩性随着显微硬度的降低而提高。压力为500MPa时,显微硬度对粉末压缩性的影响最大。

Special natural micro-alloyed iron powder prepared by reduction and grinding method has excellent performance. Effects of different annealing temperature on the compressibility of micro-alloyed iron powder were studied to increase its compressibility. Using scanning electron microscopy, X-ray diffraction and micro-hardness test, the effects of grain size and microhardness on the compressibility of micro-alloyed iron powder were discussed. The results show that powder morphology, loose packed density and flowability has little change under different annealing temperature. Annealing temperature has a great influence on grain size and micro-hardness of micro alloyed iron powder, which affects the compressibility. With the increase of annealing temperature, grain size of the iron powder increases and the micro-hardness decreases. The compressibility of the iron powder increases with the increase of grain size, and increases with the decrease of microhardness under the same pressure. When the pressure is 500 MPa, the microhardness has the largest influence on powder compressibility.