The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The diffe...The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.展开更多
Edge defects significantly impact the forming quality of Mg/Al composite plates during the rolling process.This study aims to develop an effective rolling technique to suppress these defects.First,an enhanced Lemaitre...Edge defects significantly impact the forming quality of Mg/Al composite plates during the rolling process.This study aims to develop an effective rolling technique to suppress these defects.First,an enhanced Lemaitre damage model with a generalized stress state damage prediction mechanism was used to evaluate the key mechanical factors contributing to defect formation.Based on this evaluation,an embedded composite rolling technique was proposed.Subsequently,comparative validation was conducted at 350℃ with a 50% reduction ratio.Results showed that the plates rolled using the embedded composite rolling technique had smooth surfaces and edges,with no macroscopic cracks observed.Numerical simulation indicated that,compared to conventional processes,the proposed technique reduced the maximum edge stress triaxiality of the plates from-0.02 to-1.56,significantly enhancing the triaxial compressive stress effect at the edges,which suppressed void nucleation and growth,leading to a 96%reduction in damage values.Mechanical property evaluations demonstrated that,compared to the conventional rolling process,the proposed technique improved edge bonding strength and tensile strength by approximately 67.7%and 118%,respectively.Further microstructural characterization revealed that the proposed technique,influenced by the restriction of deformation along the transverse direction(TD),weakened the plastic flow in the TD and enhanced plastic flow along the rolling direction(RD),resulting in higher grain boundary density and stronger basal texture.This,in turn,improved the toughness and transverse homogeneity of the plates.In summary,the embedded composite rolling technique provides crucial technical guidance for the preparation of Mg-based composite plates.展开更多
In Ti-Al laminated composites,cracks nucleate preferentially at the Al_(3)Ti layer,but the inhibitory effect of Al_(3)Ti on crack extension is ignored.Interestingly,by combining experiment and phase-field crystal simu...In Ti-Al laminated composites,cracks nucleate preferentially at the Al_(3)Ti layer,but the inhibitory effect of Al_(3)Ti on crack extension is ignored.Interestingly,by combining experiment and phase-field crystal simulation,we found that the micrometer Al_(3)Ti particles in the diffusion layer play the role of crack deflection and passivation,which is attributed to the lattice distortion induced by Al_(3)Ti consumes the energy of the crack in extension.In addition,it is found that the growth process of Al_(3)Ti is divided into two stages:nucleation stage and growth stage.Compared with the growth stage,the Al_(3)Ti grains in the nucleation stage are finer in the growth layer.Finer grains show better crack deflection and avoid stress concentration.展开更多
基金the National Key Research and Development Program of China(No.2018YFE0306103)the National Natural Science Foundation of China(No.52071050)+1 种基金the Science and Technology Innovation Project of Ningbo,China(No.2021Z032)the Program of China Scholarships Council(No.202106060148).
文摘The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.
基金supported by National Key Research and Development Program(2018YFA0707300)Major Program of National Natural Science Foundation of China(U22A20188).
文摘Edge defects significantly impact the forming quality of Mg/Al composite plates during the rolling process.This study aims to develop an effective rolling technique to suppress these defects.First,an enhanced Lemaitre damage model with a generalized stress state damage prediction mechanism was used to evaluate the key mechanical factors contributing to defect formation.Based on this evaluation,an embedded composite rolling technique was proposed.Subsequently,comparative validation was conducted at 350℃ with a 50% reduction ratio.Results showed that the plates rolled using the embedded composite rolling technique had smooth surfaces and edges,with no macroscopic cracks observed.Numerical simulation indicated that,compared to conventional processes,the proposed technique reduced the maximum edge stress triaxiality of the plates from-0.02 to-1.56,significantly enhancing the triaxial compressive stress effect at the edges,which suppressed void nucleation and growth,leading to a 96%reduction in damage values.Mechanical property evaluations demonstrated that,compared to the conventional rolling process,the proposed technique improved edge bonding strength and tensile strength by approximately 67.7%and 118%,respectively.Further microstructural characterization revealed that the proposed technique,influenced by the restriction of deformation along the transverse direction(TD),weakened the plastic flow in the TD and enhanced plastic flow along the rolling direction(RD),resulting in higher grain boundary density and stronger basal texture.This,in turn,improved the toughness and transverse homogeneity of the plates.In summary,the embedded composite rolling technique provides crucial technical guidance for the preparation of Mg-based composite plates.
基金supported by the National Natural Science Foundation of China(Nos.52375394,52074246,52275390,52205429,52201146)the National Defense Basic Scientific Research Program of China(JCKY2020408B002)the Key Research and Development Program of Shanxi Province(202102050201011,202202050201014).
文摘In Ti-Al laminated composites,cracks nucleate preferentially at the Al_(3)Ti layer,but the inhibitory effect of Al_(3)Ti on crack extension is ignored.Interestingly,by combining experiment and phase-field crystal simulation,we found that the micrometer Al_(3)Ti particles in the diffusion layer play the role of crack deflection and passivation,which is attributed to the lattice distortion induced by Al_(3)Ti consumes the energy of the crack in extension.In addition,it is found that the growth process of Al_(3)Ti is divided into two stages:nucleation stage and growth stage.Compared with the growth stage,the Al_(3)Ti grains in the nucleation stage are finer in the growth layer.Finer grains show better crack deflection and avoid stress concentration.
