尺寸和球磨对细晶钨粉烧结体致密度的影响

Influence of Size and Ball-Milling on Sintered Body Density of Fine Tungsten Powder

采用溶胶喷雾干燥-煅烧-氢热还原法制备了粒径为0.14μm的超细纯钨粉末。研究不同球磨(干磨,湿磨)方式对钨粉形貌以及粉末成形性的影响,探讨纯钨样品性能随样品不同尺寸(2.5mm厚小样品和2cm厚大样品)的变化。此外还详细研究了纯钨烧结体组织形貌、晶粒尺寸等性能随球磨方式及样品尺寸的变化规律。结果表明,使用干磨法和湿磨法球磨处理都可以有效提高粉末的成形性。使用干磨法球磨制备的粉末的烧结体致密度高于湿磨法所制备的,且在大尺寸样品中其致密度分布也较湿磨法所制备粉末的烧结体更加均匀。湿磨粉颗粒粒径分布较广,颗粒容易长大。干磨粉由于活化效果较弱,烧结体颗粒更加细小。

The fine pure tungsten powder with a particle size of 0.14μm was prepared by sol spray dryingcalcination-hydrogen reduction process.The influences of ball-milling ways（dry-milling and wet-milling）on the tungsten powder morphology and powder formability were investigated,the changes of pure tungsten sample properties with sample size（small samples with a thickness of 2.5 mm and big samples with a thickness of 2 cm）were explored.Additionally,the change rules of properties such as the sintered body microstructure morphology and the grain size with ball-milling ways and sample sizes were studied in detail.Results showed that powder formability was greatly improved by dry-milling and wet-milling.The densities of dry-milling sintered bodies were obviously higher than the other ones.At the same time,the density distribution of dry-milling sintered bodies was more uniform in big samples.The wet-milling powder had a wider particle size distribution,so the particles of wet-milling powder sintered bodies tended to grow up.The dry-milling powder had a weak activation effect,thus the dry-milling powder sintered body had finer particles.