强流脉冲碳离子束强化T5K10刀具机理研究

SURFACE TREATMENT OF HARD ALLOY TOOL BY HIGHINTENSITY PULSED ION BEAMS

采用TIA-450自绝缘二极管碳离子加速器对T5K10刀具进行了强流脉冲离子束辐照表面处理,加速器的加速电压为250keV,束流密度为60A/cm2～150A/cm2,脉冲时间为80纳秒,脉冲次数为2次.XRD、SEM、EDS以及显微硬度分析研究结果表明:当束流密度达到100A/cm2,材料表面为完全熔化凝固组织;当束流密度达到150A/cm2时,表面层下也出现熔化凝固组织;熔化凝固组织没有明显相变.在100A/cm2～150A/cm2内,同未辐照表面相比,显微硬度提高1.25倍.硬度增加的主要原因是表面快速凝固组织产生硬化相和基体相中化学成分的重新分布、碳元素的烧损以及晶界的强化.

Modification of hard alloy tools of T5K10 has been made by high intens ity pulse ion beams with various current density of 60 A/cm^2 , 100 A/cm^2 and 150 A/cm^2 respectively,with TIA-450 accelerator under the conditio ns of voltage 250 keV ,pulsed dur ation 80 ns and two pulse.By means of XRD,SEM?EDS and microhardness analyzin g it is revealed that asurface layer was fully remelted with current density 100 A/cm^2 and 150 A/cm^2 respectively.When irradiation with current density of 100 A/cm^2 ,surface microhardness increased to 1 25 times of that of the un-treated samples,but with 150 A/cm^2 ,the surface microhardness dose not further increase,as well as not induce farther changes of phase constituents.It is indicated that the quick s olidification of remelted surface layer results in a metastable microstroucture w ith refined greins,numerous gerain baundaries and defects etc.,which may then be responsible to the highe surface hardness.