基于共振浇注工艺的柴油机缸体微观组织与力学性能OA

To solve the shrinkage porosities and uneven tensile strength problems of gray cast iron cylinder blocks based on the traditional static casting,resonant casting tests were conducted on a six-cylinder diesel engine block with self-developed resonant casting equipment,and resonant casting were compared with the static casting.The resonant casting parameters include 5 000～5 200 r/min resonant speed,15 min resonant duration and 20～25 m/s2 acceleration.Results show that the pour-then-vibrate scheme delivers an optimal material performance.Graphite whose morphology achieves 100%is classified as Type A.The average tensile strength reaches 308.4 MPa,showing a 70.14%improvement in uniformity and a 38.3 MPa increase compared to that of static casting,while the average hardness rises to 192.2 HB,increasing by 11.9 HB compored to that of static casting.Surface inspection revealed the absence of shrinkage cavities or sand inclusions in pour-then-vibrate blocks.Conversely,both static casting and vibrate-then-pour blocks exhibited surface defects such as sand inclusions and shrinkage porosities,and the surface defects in vibrate-then-pour blocks were attributed to improper vibration timing.The resonant casting simultaneously enhances tensile strength uniformity and suppresses surface defects in cylinder blocks.