AM30 was inoculated by MgCO_(3) powder with different holding time.The influence of MgO decomposed by MgCO_(3)on the grain refinement effect was mainly discussed in the present study.Three sets of comparative samples ...AM30 was inoculated by MgCO_(3) powder with different holding time.The influence of MgO decomposed by MgCO_(3)on the grain refinement effect was mainly discussed in the present study.Three sets of comparative samples were prepared.They were AM30 alloy inoculated by MgO and pure Mg inoculated by MgO and MgCO_(3).The possible nucleating particles were observed and analyzed by EPMA and SEM.AM30 alloy could be effectively refined by either MgCO_(3)or MgO inoculation.Grain refining efficiency and fading effect of MgO inoculation were better than those of MgCO_(3) inoculation.However,pure Mg could not be refined by these two inoculants.Al is an indispensable element to determine the grain refinement of Mg alloys inoculated by either MgCO_(3)or MgO.MgO should not be the effective substrates forα-Mg phase.A novel grain refining mechanism of MgCO_(3) inoculation on AM30 alloy was proposed by combining experimental results with theoretical calculation,i.e.,MgAl_(2)O_(4) should be the potent nuclei ofα-Mg grain for the AM30 alloy in addition to Al_(4)C_(3).展开更多
基金the National Natural Science Foundation of China(51574127)Natural Science Foundation of Guangdong Province(2014A030313221).
文摘AM30 was inoculated by MgCO_(3) powder with different holding time.The influence of MgO decomposed by MgCO_(3)on the grain refinement effect was mainly discussed in the present study.Three sets of comparative samples were prepared.They were AM30 alloy inoculated by MgO and pure Mg inoculated by MgO and MgCO_(3).The possible nucleating particles were observed and analyzed by EPMA and SEM.AM30 alloy could be effectively refined by either MgCO_(3)or MgO inoculation.Grain refining efficiency and fading effect of MgO inoculation were better than those of MgCO_(3) inoculation.However,pure Mg could not be refined by these two inoculants.Al is an indispensable element to determine the grain refinement of Mg alloys inoculated by either MgCO_(3)or MgO.MgO should not be the effective substrates forα-Mg phase.A novel grain refining mechanism of MgCO_(3) inoculation on AM30 alloy was proposed by combining experimental results with theoretical calculation,i.e.,MgAl_(2)O_(4) should be the potent nuclei ofα-Mg grain for the AM30 alloy in addition to Al_(4)C_(3).
