纳米准晶增强Mg-Zn-Y合金室温具有超高延伸率,具有较广阔的应用前景,需进一步研究其热变形行为,为后续加工提供理论和应用基础。本工作采用半固态+热挤压的复合工艺制备了含有纳米准晶颗粒的Mg-1.92Zn-0.34Y(质量分数,下同)合金,探究本...纳米准晶增强Mg-Zn-Y合金室温具有超高延伸率,具有较广阔的应用前景,需进一步研究其热变形行为,为后续加工提供理论和应用基础。本工作采用半固态+热挤压的复合工艺制备了含有纳米准晶颗粒的Mg-1.92Zn-0.34Y(质量分数,下同)合金,探究本合金在250、300和350℃温度和10^(-3)、10^(-2)和10^(-1)s^(-1)应变速率条件下的高温变形机制,着重研究微量纳米准晶颗粒对Mg-1.92Zn-0.34Y合金热变形行为的影响。结果表明:半固态+热挤压的复合工艺制备了高塑性纳米准晶Mg-1.92Zn-0.34Y合金,其室温下抗拉延伸率为44%±2.6%,抗拉强度为258±2.0 MPa,屈服强度为176±1.6 MPa。通过本构关系获得平均变形激活能达到271.7812 k J/mol,其应力指数为6.7838;Mg-1.92Zn-0.34Y合金具有较好的热塑性,在研究条件下无失稳现象,表明纳米准晶颗粒能够强化其变形能力;最佳热加工区域是:330~350℃,10^(-3)~10^(-2)s^(-1),即高温低应变速率区。展开更多
In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased...In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.展开更多
文摘纳米准晶增强Mg-Zn-Y合金室温具有超高延伸率,具有较广阔的应用前景,需进一步研究其热变形行为,为后续加工提供理论和应用基础。本工作采用半固态+热挤压的复合工艺制备了含有纳米准晶颗粒的Mg-1.92Zn-0.34Y(质量分数,下同)合金,探究本合金在250、300和350℃温度和10^(-3)、10^(-2)和10^(-1)s^(-1)应变速率条件下的高温变形机制,着重研究微量纳米准晶颗粒对Mg-1.92Zn-0.34Y合金热变形行为的影响。结果表明:半固态+热挤压的复合工艺制备了高塑性纳米准晶Mg-1.92Zn-0.34Y合金,其室温下抗拉延伸率为44%±2.6%,抗拉强度为258±2.0 MPa,屈服强度为176±1.6 MPa。通过本构关系获得平均变形激活能达到271.7812 k J/mol,其应力指数为6.7838;Mg-1.92Zn-0.34Y合金具有较好的热塑性,在研究条件下无失稳现象,表明纳米准晶颗粒能够强化其变形能力;最佳热加工区域是:330~350℃,10^(-3)~10^(-2)s^(-1),即高温低应变速率区。
基金This research project was supported by the National Natural Science Foundation of China(No.52074138)Basic research project of Yunnan Province(No.202001AS070030)Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2020-03).
文摘In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.
