Influence of Iron Nanopowder Addition on Sintering of Water Atomized Iron Powder
There is a constant drive for improvement of the density of powder metallurgy(PM)steels as they are known to offer cost-effective solutions for structural applications.Increase in the density of PM steels will expand their use in applications demanding higher performance than what they deliver today.One of the promising ways to improve densification is through the utilization of powder mixes with different size fractions.Admixing nanopowder can contribute to higher sinter-density of compacts having micrometer-sized powder as main constituent,typically used for manufacturing PM steel components.The higher surface to volume ratio of nanopowder is hypothesized to contribute to densification by increasing the inter-particle contact area.This is supposed to enhance the material transport path and improve the densification.In the present investigation,nanopowder(40-60 nm)was added to water atomized iron powder(-45 μm).This approach was to study the influence of nanopowder addition on the sintering of iron powder.The weight percent of nanopowder was varied to help understanding the densification provided by the addition.This mixed powder was compacted at 800 MPa followed by sintering of up to 1350 ℃ in pure H2 atmosphere.The sintering behavior was studied by means of dilatometry and thermal analysis followed by microstructural and fractographic characterization in order to elucidate the effect of nanopowder on densification.It was shown that the linear shrinkage increased from 1.5 to 2.5%when the nanopowder content was increased from 5 to 15 wt.%.Significant changes during the sintering of the compacts were observed between 500 to 700 ℃ due to the nanopowder addition.
Nanopowder Dilatometry Low temperature sintering Fractography
Manchili Swathi K. Wendel Johan Hryha Eduard Nyborg Lars
Department of Industrial and Materials Science,Chalmers University of Technology,de R(a)nnv(a)gen 2A,Gothenburg 41956,Sweden
国际会议
北京
英文
509-514
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）