Effects Of Rolling On Microstructure And Properties Of ?ZrB₂+TiB₂?/AlSi9Cu1 Composites

In this paper,the?ZrB₂+TiB₂?/AlSi9Cu1 composites are prepared by melt reaction method,and rolled in different ways to different rolling materials.The effects of rolling on the microstructure of the composites are observed by means of SEM,EDS,OM and XRD.The changes of the harmful phase,the distributions of the particles and the changes of the grain size are observed under different rolling conditions by these means.The mechanical properties of composite materials in different rolling states are tested to understand the strengthening mechanism of rolling materials.The effects of heat treatment on the rolling composites are investigated by microstructure observation and mechanical properties analysis.The effects of rolling on the microstructure of?ZrB₂+TiB₂?/AlSi9Cu1 composites show that the Al-Fe phase and the Al-Ti-Zr phase in the composite matrix are“disappeared” by 6 passes hot rolling+4 passes cold rolling.Some of the harmful phases in the composite phase can be eliminated by rolling.Large deformation of the hot rolling can make the silicon phase fragmentation,and the fragmented small silicon phase diffuses through hot rolling.Small deformation of the cold rolling is the main reason for the jaggedness of the edge of the silicon phase.The morphology of the silicon phase can be optimized by a certain amount of hot rolling + cold rolling.The topography of silicon phase in composites and microstructure of composite materials are the best by 6 passes hot rolling+4 passes cold rolling.The composite materials appear to recovery,dynamic recovery,recrystallization and recrystallization grain growth phenomenon by rolling.The reason for these phenomena is related to the rolling pressure and the rolling temperature.Through the study of the tensile curves of the?ZrB₂+TiB₂?/AlSi9Cu1 composites show that the dynamic strain aging?DSA?effect of?Zr B2+TiB2?/AlSi9Cu1 composites is closely related to the microstructure of the composites during the stretching process.The tensile strength and elongation of the?ZrB₂+TiB₂?/AlSi9Cu1 composites are improved and the mechanical properties are improved by rolling.The cold rolling after hot rolling can greatly improve the tensile strength of the composites,the main reason for this phenomena is that the material has a hardening effect during the cold rollingprocessing.?ZrB₂+TiB₂?/AlSi9Cu1 composites are the highest tensile strength of287 MPa,and the elongation is 17.6% after 6 passes hot rolling and 4 passes cold rolling.Compared with the non-rolled composite material,its tensile strength is increased by 40.7%,elongation increased by 79.6%.The effect of heat treatment on the microstructure of?ZrB₂+TiB₂?/Al Si9Cu1 composites shows that the heat treatment can make the silicon phase become ellipsoid,which greatly optimizes the silicon phase morphology.And the recrystallization and recovery phenomenon in composite materials can be eliminated by heat treatment.The effect of heat treatment on the mechanical properties of?ZrB₂+TiB₂?/AlSi9Cu1 composites show that the tensile strength of the rolled composites is reduced after heat treatment and the heat treatment eliminates the hardening effect of cold rolling.After heat treatment,the dynamic strain aging phenomenon occurs again in composites because that the heat treatment eliminates the effect of partial rolling.The mechanical properties of?ZrB₂+TiB₂?/AlSi9Cu1 composites after 6 passes hot rolling+4 passes cold rolling are the best,the tensile strength is 247 MPa and the elongation is26.7%.Compared with the non-heated treatment composite material,its elongation increased by 51.7%,however,its tensile strength decreased by 16%.