湖南大学学报(自然科学版)
湖南大學學報(自然科學版)
호남대학학보(자연과학판)
JOURNAL OF HUNAN UNIVERSITY(NATURAL SCIENCES EDITION)
2014年
7期
23-29
,共7页
刘志文%李落星%肖罡%姚再起
劉誌文%李落星%肖罡%姚再起
류지문%리락성%초강%요재기
铝型材%弯曲回弹%热处理状态%工艺顺序%数值仿真
鋁型材%彎麯迴彈%熱處理狀態%工藝順序%數值倣真
려형재%만곡회탄%열처리상태%공예순서%수치방진
aluminum profiles%springback%heat-treated condition%process sequences%simulation
采用实验和数值仿真相结合的方法研究了材料热处理状态和工艺顺序对6063铝型材弯曲回弹的影响规律和机理。结果表明:型材绕弯变形区内外层材料分别为压应力和拉应力起主导作用,中性层附近材料为明显的拉压两向应力集中区。外力卸载后,中性层存在很大的残余拉应力;挤压态型材经人工时效处理后绕弯成形回弹角将会变大。且随着人工时效时间的延长,内外侧材料最大拉压应力差变大,回弹角逐渐增大;弯曲型材后续经人工时效或电泳烤漆处理,产生二次回弹。且弯曲角度越大,热处理后回弹角会增大。进一步延长人工时效时间,弯曲型材的回弹角基本不变;弯曲型材的三种成形工艺顺序方案中,挤压态型材先经冷弯成形再紧接着进行人工时效和电泳烤漆处理总的回弹角最小。
採用實驗和數值倣真相結閤的方法研究瞭材料熱處理狀態和工藝順序對6063鋁型材彎麯迴彈的影響規律和機理。結果錶明:型材繞彎變形區內外層材料分彆為壓應力和拉應力起主導作用,中性層附近材料為明顯的拉壓兩嚮應力集中區。外力卸載後,中性層存在很大的殘餘拉應力;擠壓態型材經人工時效處理後繞彎成形迴彈角將會變大。且隨著人工時效時間的延長,內外側材料最大拉壓應力差變大,迴彈角逐漸增大;彎麯型材後續經人工時效或電泳烤漆處理,產生二次迴彈。且彎麯角度越大,熱處理後迴彈角會增大。進一步延長人工時效時間,彎麯型材的迴彈角基本不變;彎麯型材的三種成形工藝順序方案中,擠壓態型材先經冷彎成形再緊接著進行人工時效和電泳烤漆處理總的迴彈角最小。
채용실험화수치방진상결합적방법연구료재료열처리상태화공예순서대6063려형재만곡회탄적영향규률화궤리。결과표명:형재요만변형구내외층재료분별위압응력화랍응력기주도작용,중성층부근재료위명현적랍압량향응력집중구。외력사재후,중성층존재흔대적잔여랍응력;제압태형재경인공시효처리후요만성형회탄각장회변대。차수착인공시효시간적연장,내외측재료최대랍압응력차변대,회탄각축점증대;만곡형재후속경인공시효혹전영고칠처리,산생이차회탄。차만곡각도월대,열처리후회탄각회증대。진일보연장인공시효시간,만곡형재적회탄각기본불변;만곡형재적삼충성형공예순서방안중,제압태형재선경랭만성형재긴접착진행인공시효화전영고칠처리총적회탄각최소。
Methods in numerical simulation combined with experiments were used to study the influence of heat-treated condition and process sequences on the springback of 6063 aluminum bent profiles.The re-sults show that the inner and outer materials of profile cross-section during bending process suffer com-pressive and tensile stress,while the nearby neutral fiber suffers an obvious tensile-compressive stress con-centration.The neutral fiber of the whole plastic deformation region has a larger residual tensile stress af-ter unloading.The springback angle of extruded profile increases after artificial aging.With the increase of artificial aging time,the difference of maximum tensile and compressive stress between the inner and outer materials increases,and consequently,the springback angle gradually increases.The curved profile also rebounds after artificial aging and electrophoresis paint,and with the increase of the bending angle,the springback angle increases.The artificial aging time further increases,but the rebound angle of curved profile remains unchanged.The total springback angle is minimum when the extruded profile is first pro-cessed by cold bending,and then by artificial aging and electrophoresis painting.