CAJ | 학술논문

A356铝合金挤压铸造的储气筒在其局部补压位置附近出现环形斑,对应一次补压和二次补压为单环斑和双环斑,环形斑直径分别为33和61 mm,斑痕宽度0．6~2 mm；环形斑处硅含量高于平均值29％,其中共晶体相对含量约是合金平均值8．5倍；局部补压使处于固液两相状态区域内的液相与固相分离,液体流动方向与补挤方向相反,因此造成成分偏析和偏析组织；偏析处微观组织与正常基体之间保持键合完整性、无裂纹等缺陷,储气筒零件仍然满足使用要求的气密性和耐压性.
A356려합금제압주조적저기통재기국부보압위치부근출현배형반,대응일차보압화이차보압위단배반화쌍배반,배형반직경분별위33화61 mm,반흔관도0．6~2 mm；배형반처규함량고우평균치29％,기중공정체상대함량약시합금평균치8．5배；국부보압사처우고액량상상태구역내적액상여고상분리,액체류동방향여보제방향상반,인차조성성분편석화편석조직；편석처미관조직여정상기체지간보지건합완정성、무렬문등결함,저기통령건잉연만족사용요구적기밀성화내압성.
Circular spots take place on the surface near local filling squeezing puncher pin of an A356 aluminum alloy squeeze casting air cylinder.Corresponds to one filling squeezing and the twice filling squeezing monocyclic and bicyclic spots,the circle spot diameter were 33 and 61 mm,its width 0.6-2 mm.The silicon content at circle spot exceeds 29% above the average of the alloy,about 8.5 times the average relative content of the eutectic in alloy.Local filling squeezing in the area of solid-liquid two-phase resulted in the liquid separating from solid, liquid flow direction opposite to the direction of extrusion,then resulting component segregation and segrega-tion microstructure.Segregation microstructure with normal matrix microstructure to maintain the integrity of the bonding,no defects such as cracks,the air cylinder part still meet use airtight and pressure resistance re-quirements.