冲击载荷下灰口铸铁力学行为的率效应及其破坏特性  

Study on Mechanical Properties of Strain-Rate Effect and its Failure Mode for Cast Iron under Impact Loading

作　　者：董新龙[1] 王礼立[1] 李深智[2] 许正勋 

机构地区：[1]宁波大学力学与材料科学研究中心,浙江宁波315211 [2]台湾大同大学材料工程系

出　　处：《宁波大学学报（理工版）》2000年第2期12-15,共4页Journal of Ningbo University：Natural Science and Engineering Edition

摘　　要：利用ＳＨＰＢ压杆及Ｉｎｓｔｒｏｎ液压伺服村料试验机对灰口铸铁从准静态（应变率１０^（－４）ｓ－１）到冲击动态（应变率 ４ ｘ １０３ｓ－１）进行了宏观与微观相结合的试验研究，得到了该材料在不同应变率下的应力－应变曲线．实验结果表明，灰口铸铁在塑性变形初期对应变率不敏感，随应变增大则具有一定的应变率硬化效应．但在更高应变率下随应变增大会出现反向应变率效应．这些特性与灰口铸铁源于片状石墨处内部微裂纹成核、长大、聚集的演化过程以及这一演化程过的应变率相关性是密切相关的．By SHPB method and INSTRON test machine, the mechanical behavior of flaky graphite cast iron was studied in a strain-rate range from 10-4 to 3 x 103 s- 1 and the stress-strain curves was obtained. Results show that the flow stress of this cast alloy appear almost no strain sensitivity at the beginning of plastic deformation, and later appear some rate-hardening effects with development of plastic deformation. Furthermore, at higher strain-rates, flaky graphite cast iron shows negative strain-rate effect This is mainly due to the initiation, enlarging and coalesce of the micro-crack between the flaky graphite and cast alloy base.This internal damage process is also related to rate-dependent evolution.

关 键 词：动态力学行为 应变率效应 损伤演化 灰口铁 

分 类 号：TG143.2[一般工业技术—材料科学与工程]