采用原位反应近液相线铸造法制备具有不同原位TiC颗粒含量的TiCp/7075铝基复合材料,在7075铝合金固?液两相区间(477～635℃)的580和600℃进行二次加热并保温20min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸及形状因...采用原位反应近液相线铸造法制备具有不同原位TiC颗粒含量的TiCp/7075铝基复合材料,在7075铝合金固?液两相区间(477～635℃)的580和600℃进行二次加热并保温20min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸及形状因子,研究原位TiC颗粒含量对该合金二次加热组织的影响。结果表明:当原位TiC颗粒质量分数为0～4.4%时,随着原位TiC颗粒质量分数增加,合金铸态组织直接转变为等轴晶组织,且在二次加热过程中,原位TiC颗粒对晶粒的长大行为具有明显的抑制作用;在相同的二次加热条件下,4.4%TiCp/7075铝基复合材料的平均晶粒尺寸比7075基体合金的减少30～40μm,更加适合于半固态触变成形。展开更多
A kind of Al-TiB2/TiC in situ composite with a homogenous microstructure was successfully prepared through in situ reaction of pure Ti and Al-B-C alloy with molten aluminum.In order to improve the distribution of the ...A kind of Al-TiB2/TiC in situ composite with a homogenous microstructure was successfully prepared through in situ reaction of pure Ti and Al-B-C alloy with molten aluminum.In order to improve the distribution of the particles and mechanical properties of the composites,subsequent hot rolling with increasing reduction was carried out.The microstructure evolution of the composites was characterized using field emission scanning electron microscopy(FESEM)and the mechanical properties were studied through tensile tests and microhardness measurement.It is found that both the microstructure uniformity and mechanical properties of the composites are significantly improved with increasing rolling reduction.The ultimate tensile strength and microhardness of the composites with90%rolling reduction reach185.9MPa and HV59.8,respectively,140%and35%higher than those of as-cast ones.Furthermore,the strengthening mechanism of the composite was analyzed based on the fracture morphologies.展开更多
采用原位反应近液相线铸造方法制备4.4%TiCP/7075铝复合材料,在基体合金的液-固两相区间（477～635℃）的600℃分别保温10、20、40、60 min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸,研究原位TiCP对二次加热组织...采用原位反应近液相线铸造方法制备4.4%TiCP/7075铝复合材料,在基体合金的液-固两相区间（477～635℃）的600℃分别保温10、20、40、60 min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸,研究原位TiCP对二次加热组织的影响。结果表明,原位TiCP不仅使合金铸态组织直接转变为等轴晶组织,而且在二次加热过程中,对晶粒的长大行为具有明显的抑制作用。在相同的二次加热条件下,TiCP/7075铝复合材料的平均晶粒尺寸比7075基体合金减小了30～40μm,更适合于半固态触变成形。展开更多
An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS...An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS) and X-ray diffraction(XRD).The results show that the Al-3Ti-0.2C-1RE grain refiner is composed of α-Al,TiAl3,TiC and Ti2 Al20 Ce phases.Compared with Al-3Ti-0.2C refiner,the morphology of TiAl3 phase is changed and Ti2 Al20 Ce phases form with the addition of RE.Accordingly,the refining performance is improved.The phase forming process of the refiner is as follows: Blocky Ti2 Al20 Ce and fine blocky TiAl3 form in the melt at the initial stage of reaction,then the fine blocky TiAl3 gradually disappears,and the blocky Ti2 Al20 Ce grows bigger with the increase of holding time.The predominant mechanism to synthesize TiC particles is the reaction between high concentration of solute Ti atoms and graphite particles.展开更多
文摘采用原位反应近液相线铸造法制备具有不同原位TiC颗粒含量的TiCp/7075铝基复合材料,在7075铝合金固?液两相区间(477～635℃)的580和600℃进行二次加热并保温20min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸及形状因子,研究原位TiC颗粒含量对该合金二次加热组织的影响。结果表明:当原位TiC颗粒质量分数为0～4.4%时,随着原位TiC颗粒质量分数增加,合金铸态组织直接转变为等轴晶组织,且在二次加热过程中,原位TiC颗粒对晶粒的长大行为具有明显的抑制作用;在相同的二次加热条件下,4.4%TiCp/7075铝基复合材料的平均晶粒尺寸比7075基体合金的减少30～40μm,更加适合于半固态触变成形。
基金Project(51501092)supported by the National Natural Science Foundation of ChinaProject(30915011332)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2014M550292)supported by China Postdoctoral Science Foundation
文摘A kind of Al-TiB2/TiC in situ composite with a homogenous microstructure was successfully prepared through in situ reaction of pure Ti and Al-B-C alloy with molten aluminum.In order to improve the distribution of the particles and mechanical properties of the composites,subsequent hot rolling with increasing reduction was carried out.The microstructure evolution of the composites was characterized using field emission scanning electron microscopy(FESEM)and the mechanical properties were studied through tensile tests and microhardness measurement.It is found that both the microstructure uniformity and mechanical properties of the composites are significantly improved with increasing rolling reduction.The ultimate tensile strength and microhardness of the composites with90%rolling reduction reach185.9MPa and HV59.8,respectively,140%and35%higher than those of as-cast ones.Furthermore,the strengthening mechanism of the composite was analyzed based on the fracture morphologies.
文摘采用原位反应近液相线铸造方法制备4.4%TiCP/7075铝复合材料,在基体合金的液-固两相区间（477～635℃）的600℃分别保温10、20、40、60 min,水淬固定其半固态组织,应用Image Pro Plus软件测量平均晶粒尺寸,研究原位TiCP对二次加热组织的影响。结果表明,原位TiCP不仅使合金铸态组织直接转变为等轴晶组织,而且在二次加热过程中,对晶粒的长大行为具有明显的抑制作用。在相同的二次加热条件下,TiCP/7075铝复合材料的平均晶粒尺寸比7075基体合金减小了30～40μm,更适合于半固态触变成形。
基金Project(51174177)supported by the National Natural Science Foundation of China
文摘An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS) and X-ray diffraction(XRD).The results show that the Al-3Ti-0.2C-1RE grain refiner is composed of α-Al,TiAl3,TiC and Ti2 Al20 Ce phases.Compared with Al-3Ti-0.2C refiner,the morphology of TiAl3 phase is changed and Ti2 Al20 Ce phases form with the addition of RE.Accordingly,the refining performance is improved.The phase forming process of the refiner is as follows: Blocky Ti2 Al20 Ce and fine blocky TiAl3 form in the melt at the initial stage of reaction,then the fine blocky TiAl3 gradually disappears,and the blocky Ti2 Al20 Ce grows bigger with the increase of holding time.The predominant mechanism to synthesize TiC particles is the reaction between high concentration of solute Ti atoms and graphite particles.
