INDEX C200车削中心适用于使用棒料高速车削生产零件,两个动力强劲的电主轴保证了金属切削的高效率,副主轴的快速移动速度可达50 m/min。C200可配备2或3刀塔,42个刀位和具有专利设计的W型刀具定位槽,缩短了调整时间,适合于多品种小批量...INDEX C200车削中心适用于使用棒料高速车削生产零件,两个动力强劲的电主轴保证了金属切削的高效率,副主轴的快速移动速度可达50 m/min。C200可配备2或3刀塔,42个刀位和具有专利设计的W型刀具定位槽,缩短了调整时间,适合于多品种小批量生产。极高的动力性和刀架的快速分度减少了屑对屑时间。机床的垂直床身保证了排屑流畅,工件自动卸料系统为龙门式集成工件卸料装置,保证了快速卸料,而不会损坏工件。另外,余下的残料可以单独从主轴上移出。INDEX平面移动导轨保证了机床较高的动力性和最佳的吸震性,使刀具寿命延长,工件质量提高,生产周期缩短。展开更多
A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-stati...A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-static mechanical properties (mechanical strength, toughness, fracture energy and interfacial bonding strength) of GRPC specimens, cured in three different types of regimes, are investigated. The experimental results show that the mechanical properties of the C200 GRPC made with the powder binders that is composed of 40% of Portland cement, 25% of ultra fine slag, 25% of ultra fine fly ash and 10% of silica fume are better than the others'. The corresponding compressive strength, flexural strength and fracture energy are more than 200 MPa, and 30 000 J/ m2 respectively. The dynamic tensile behavior of the C200 GRPC is also investigated through the split Hopkinson pressure bar (SHPB) according to the spalling phenomenon. The dynamic testing results demonstrate that strain rate has an important effect on the dynamic tensile behavior of GRPC. With the increase of strain rate, its peak stress and relevant strain increase. The GRPC exhibits an excellent strain ratio stiffening effect under the dynamic tensile load with high strain ratio, resulting in a significant change of the fracture pattern.展开更多
基金Supported by Jiangsu Province Natural Science Foundation Project (No. BK 20065)China National Military Engineering Project (No. A1420060186)
文摘A new type of green reactive powder concrete (GRPC) with compressive strength of 200 MPa is prepared by utilizing composite mineral admixtures, natural fine aggregates, and short and fine steel fibers. The quasi-static mechanical properties (mechanical strength, toughness, fracture energy and interfacial bonding strength) of GRPC specimens, cured in three different types of regimes, are investigated. The experimental results show that the mechanical properties of the C200 GRPC made with the powder binders that is composed of 40% of Portland cement, 25% of ultra fine slag, 25% of ultra fine fly ash and 10% of silica fume are better than the others'. The corresponding compressive strength, flexural strength and fracture energy are more than 200 MPa, and 30 000 J/ m2 respectively. The dynamic tensile behavior of the C200 GRPC is also investigated through the split Hopkinson pressure bar (SHPB) according to the spalling phenomenon. The dynamic testing results demonstrate that strain rate has an important effect on the dynamic tensile behavior of GRPC. With the increase of strain rate, its peak stress and relevant strain increase. The GRPC exhibits an excellent strain ratio stiffening effect under the dynamic tensile load with high strain ratio, resulting in a significant change of the fracture pattern.
