Yttria-reinforced copper matrix composites were prepared by dry ball milling （DBM） and wet ball milling （WBM）, respectively, followed by spark plasma sintering （SPS）. It is to determine which milling process is ...Yttria-reinforced copper matrix composites were prepared by dry ball milling （DBM） and wet ball milling （WBM）, respectively, followed by spark plasma sintering （SPS）. It is to determine which milling process is better for fabricating Cu-Y2O3 composites. It is found that Cu-Y2O3 composites synthesized by DBM exhibit better densification, mechanical and electrical properties than those by WBM. Less agglomeration of reinforcements in the bulk composites by DBM is responsible for the better perfor- mances. To further understand the reason of less agglomeration of Y2O3 in the bulks by DBM, morphologies of prepared powders were investigated and analyzed. Higher ball＇s impact energy and the formation of copper oxide on the matrix surface during DBM process contribute to small matrix particles, which is beneficial for less agglomeration.展开更多
Indian hematite fines are normally characterized by high iron grade and minor impurities, which are usually used for sinter fines. With macroscale operations technology of blast furnace in Indian, pellets, as a kind o...Indian hematite fines are normally characterized by high iron grade and minor impurities, which are usually used for sinter fines. With macroscale operations technology of blast furnace in Indian, pellets, as a kind of high-quality materials, attract more and more attention. However, the hematite fines possess the coarse size. Hence, they inevitably need to be further finely ground for pelletizing before balling. The grinding behavior of Indian hematite fines was revealed by conducting the ball milling tests and determining the Bond ball mill work index （Wi）. The results show that Indian hematite fines have an excellent grindability with Wi of only 7.40-7.73 kWh/t, indicating that ball milling is an economically viable way to pretreat Indian hematite fines. Nonetheless, due to poor sedimentation and filtering properties of wet ground products, the dry ball milling is more appropriate to process Indian hematite fines. In addition, the superior quality green balls can be manufactured with dry ground products under the conditions of 0.5% bentonite dosage, 7.5% moisture and balling for 12 min, which further confirmed that the recommended pellet feed preparation technique is reasonable.展开更多
基金financially supported by the National Key Research and Development Program of China (No. 2016YFB0301400)the Organization Department of Jiangxi Province(No. 2012215)+1 种基金the Education Department of Jiangxi Province (No. KJLD13041)the Outstanding Doctoral Dissertation Project Fund of JXUST (No. YB2017011)
文摘Yttria-reinforced copper matrix composites were prepared by dry ball milling （DBM） and wet ball milling （WBM）, respectively, followed by spark plasma sintering （SPS）. It is to determine which milling process is better for fabricating Cu-Y2O3 composites. It is found that Cu-Y2O3 composites synthesized by DBM exhibit better densification, mechanical and electrical properties than those by WBM. Less agglomeration of reinforcements in the bulk composites by DBM is responsible for the better perfor- mances. To further understand the reason of less agglomeration of Y2O3 in the bulks by DBM, morphologies of prepared powders were investigated and analyzed. Higher ball＇s impact energy and the formation of copper oxide on the matrix surface during DBM process contribute to small matrix particles, which is beneficial for less agglomeration.
基金The authors would like to acknowledge the Analytical and Testing Center of Central South University to supply the facilities to fulfill the measurements. The authors also wish to express their thanks to the National Natural Science Foundation of China （No. 51474161） and Hunan Provincial Innovation Foundation for Postgraduate （CX2017B056） for the financial support of this research.
文摘Indian hematite fines are normally characterized by high iron grade and minor impurities, which are usually used for sinter fines. With macroscale operations technology of blast furnace in Indian, pellets, as a kind of high-quality materials, attract more and more attention. However, the hematite fines possess the coarse size. Hence, they inevitably need to be further finely ground for pelletizing before balling. The grinding behavior of Indian hematite fines was revealed by conducting the ball milling tests and determining the Bond ball mill work index （Wi）. The results show that Indian hematite fines have an excellent grindability with Wi of only 7.40-7.73 kWh/t, indicating that ball milling is an economically viable way to pretreat Indian hematite fines. Nonetheless, due to poor sedimentation and filtering properties of wet ground products, the dry ball milling is more appropriate to process Indian hematite fines. In addition, the superior quality green balls can be manufactured with dry ground products under the conditions of 0.5% bentonite dosage, 7.5% moisture and balling for 12 min, which further confirmed that the recommended pellet feed preparation technique is reasonable.
