精密成形工程
精密成形工程
정밀성형공정
METAL FORMING TECHNOLOGY
2012年
6期
71-77
,共7页
半固态%等径角挤压%3A21铝合金%等积圆直径%形状系数
半固態%等徑角擠壓%3A21鋁閤金%等積圓直徑%形狀繫數
반고태%등경각제압%3A21려합금%등적원직경%형상계수
semi solid%ECAP%3A21 aluminum alloy%equal area circle diameter%shape factor
以3A21铝合金为研究对象,将等径角挤压工艺与等温处理工艺相结合,从实验角度研究其中的工艺参数对半固态组织尺寸形貌的影响。采用Bc路径进行ECAP3道次处理,然后在660℃下保温20,25,30min,得到27个试样的半固态组织。结果表明,随着挤压道次的增加,晶粒尺寸减小,变形更加均匀,并且累积变形能的增多,也为后续半固态等温处理提供了更好的应变诱导条件;保温时间越长,半固态组织演化越完全,晶粒球化越完整,但晶粒尺寸会随着保温时间的延长而长大。最后得出最佳工艺参数匹配:室温下沿Bc路径等径角挤压3道次,660℃下保温25min;最终半固态坯料显微组织的平均等积圆直径d=83.7μm,平均形状系数Fc=0.84。
以3A21鋁閤金為研究對象,將等徑角擠壓工藝與等溫處理工藝相結閤,從實驗角度研究其中的工藝參數對半固態組織呎吋形貌的影響。採用Bc路徑進行ECAP3道次處理,然後在660℃下保溫20,25,30min,得到27箇試樣的半固態組織。結果錶明,隨著擠壓道次的增加,晶粒呎吋減小,變形更加均勻,併且纍積變形能的增多,也為後續半固態等溫處理提供瞭更好的應變誘導條件;保溫時間越長,半固態組織縯化越完全,晶粒毬化越完整,但晶粒呎吋會隨著保溫時間的延長而長大。最後得齣最佳工藝參數匹配:室溫下沿Bc路徑等徑角擠壓3道次,660℃下保溫25min;最終半固態坯料顯微組織的平均等積圓直徑d=83.7μm,平均形狀繫數Fc=0.84。
이3A21려합금위연구대상,장등경각제압공예여등온처리공예상결합,종실험각도연구기중적공예삼수대반고태조직척촌형모적영향。채용Bc로경진행ECAP3도차처리,연후재660℃하보온20,25,30min,득도27개시양적반고태조직。결과표명,수착제압도차적증가,정립척촌감소,변형경가균균,병차루적변형능적증다,야위후속반고태등온처리제공료경호적응변유도조건;보온시간월장,반고태조직연화월완전,정립구화월완정,단정립척촌회수착보온시간적연장이장대。최후득출최가공예삼수필배:실온하연Bc로경등경각제압3도차,660℃하보온25min;최종반고태배료현미조직적평균등적원직경d=83.7μm,평균형상계수Fc=0.84。
Equal channel angular pressing and isothermal treatment were combined and the influence of technological pa-rameters on size and pattern of semi-solid microstructures of 3A21 aluminum alloy was analyzed in the view of experiments. Twenty-seven samples were obtained after 3 passes ECAP under route Be and 20, 25,30 min holding under the temperature of 660 ~C. The results indicate that, with the increment of ECAP passes, size of gains becomes smaller, deformation of micro-structure becomes more uniform, and the more accumulation of deformation energy creates a favorable strain inducement con-dition for subsequent isothermal treatment in semi-solid state; gains spheroidize better and gain size becomes larger when the heat holding time elongates. In conclusion, the best technology parameters are as follows: ECAP route Bc, 3 passes, holding temperature 660 ℃, holding time 25 min. The average gain size is 83.7 μm, and the average shape factor is 0.84.