中文摘要：

对铝合金压铸过程中早期出现开裂的H13钢对接型芯的冶金质量、显微组织、力学性能以及断口形貌进行了分析。研究表明,型芯内孔残留刀痕和原材料质量是诱发型芯开裂的重原因。服役过程中,承受最大弯曲应力的型芯内孔刀痕处容易应力集中而萌生微裂纹;在周期性载荷作用下,微裂纹沿偏析严重、力学性能薄弱区域向两侧及外径方向扩展,到达外表面后发生开裂失效。

英文摘要：

The metallurgical quality, microstructure, mechanical properties of the H13 steel die-casting cores for aluminum die casting process, and the fracture morphology on the cracking core was observed by three-dimensional optical microscopy. The results show that the tools marks on the inner holes surface of core and the quality of the H13 steel are important factors for the induced core cracking. During the aluminum die casting process, the stress concentration is easy to occur at the tools marks where it undergoes the largest bend stress, and then the mierocracks will be initiation. Under the periodic load, the microcracks extend through the place of seriously segregated and weak mechanical properties to both sides and outer radial direction. Finally, the cracks reach the outer surface of cores, and it is cracking failure.