To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the ...To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the synthetic rules of carbon saturation degree,inoculation degree and mechanical properties can be exposed.The result shows that,according to the needs of the part′s mechanical properties,referring to the synthetic rules of gray cast iron,the corresponding technological measure and composition proportion can be defined,by which we will get the exact mechanical properties that could achieve the result expected completely.Thus,the casting for gray cast iron might be 'designed'from'selected'.展开更多
The height, thickness and spacing of fins have an impact on the thermal characteristics of a radiator. The calculation of heat output and metal thermal intensity for cast iron finned radiator are given by using heat t...The height, thickness and spacing of fins have an impact on the thermal characteristics of a radiator. The calculation of heat output and metal thermal intensity for cast iron finned radiator are given by using heat transfer formula of vertical plate and parallel fins. Each factor having effect on the metal thermal intensity of a radiator is analyzed and the optimum structure parameters of a radiator are given in order to maximize metal thermal intensity.展开更多
The morphology changes of both Fe-containing intermetallic compounds and the primary Si phase of Al-20Si-2Fe- 2Cu-0.4Mg-1.0Ni-0.5Mn （mass fraction, %） alloy produced by semi-solid rheo-diecasting were studied. The s...The morphology changes of both Fe-containing intermetallic compounds and the primary Si phase of Al-20Si-2Fe- 2Cu-0.4Mg-1.0Ni-0.5Mn （mass fraction, %） alloy produced by semi-solid rheo-diecasting were studied. The semi-solid slurry of high silicon aluminum alloy was prepared by direct ultrasonic vibration （DUV） which was imposed on the alloy near the liquidus temperature for about 2 rain. Then, standard test samples of 6.4 mm in diameter were formed by semi-solid rheo-diecasting. The results show that the DUV treatment suppresses the formation of needle-like ,β-Al5（Fe,Mn）Si phase, and the Fe-containing intermetallic compounds exist in the form of fine Al4（Fe, Mn）Si2 particles. Additionally, the primary Si grows up as fine and round particles with uniform distribution in α（Al） matrix of this alloy under DUV treatment. The tensile strengths of the samples at the room temperature and 573 K are 230 MPa and 145 MPa, respectively. The coefficient of thermal expansion （CTE） between 25 ℃ and 300 ℃ is 16.052 8×10^-6 ℃^-1, and the wear rate is 1.55%. The hardness of this alloy with 2% Fe reaches HB146.3. It is discovered that modified morphology and uniform distribution of the Fe-containing intermetallic compounds and the primary Si phase are the main reasons for reducing the CTE and increasing the wear resistance of this alloy.展开更多
The work in this study is focused on the investigation of the structure and properties of ductile cast iron with nanoparticle additives： TiN （titanium nitride）, TiN ＋ TiCN （titanium carbonitride） and cBN （cubic...The work in this study is focused on the investigation of the structure and properties of ductile cast iron with nanoparticle additives： TiN （titanium nitride）, TiN ＋ TiCN （titanium carbonitride） and cBN （cubic boron nitride）. The nanoparticles are coated with nickel prior to addition to the iron melt to improve their wetting and uniform distribution in the volume of the casting. The metallographic observation and wear test are performed to study the influence of the nanoparticle additives on the microstructure and and cast iron tribological properties.展开更多
文摘To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the synthetic rules of carbon saturation degree,inoculation degree and mechanical properties can be exposed.The result shows that,according to the needs of the part′s mechanical properties,referring to the synthetic rules of gray cast iron,the corresponding technological measure and composition proportion can be defined,by which we will get the exact mechanical properties that could achieve the result expected completely.Thus,the casting for gray cast iron might be 'designed'from'selected'.
文摘The height, thickness and spacing of fins have an impact on the thermal characteristics of a radiator. The calculation of heat output and metal thermal intensity for cast iron finned radiator are given by using heat transfer formula of vertical plate and parallel fins. Each factor having effect on the metal thermal intensity of a radiator is analyzed and the optimum structure parameters of a radiator are given in order to maximize metal thermal intensity.
基金Project(2007AA03Z557) supported by the National High-tech Research and Development Program of ChinaProject(50775086) supported by the National Natural Science Foundation of China
文摘The morphology changes of both Fe-containing intermetallic compounds and the primary Si phase of Al-20Si-2Fe- 2Cu-0.4Mg-1.0Ni-0.5Mn （mass fraction, %） alloy produced by semi-solid rheo-diecasting were studied. The semi-solid slurry of high silicon aluminum alloy was prepared by direct ultrasonic vibration （DUV） which was imposed on the alloy near the liquidus temperature for about 2 rain. Then, standard test samples of 6.4 mm in diameter were formed by semi-solid rheo-diecasting. The results show that the DUV treatment suppresses the formation of needle-like ,β-Al5（Fe,Mn）Si phase, and the Fe-containing intermetallic compounds exist in the form of fine Al4（Fe, Mn）Si2 particles. Additionally, the primary Si grows up as fine and round particles with uniform distribution in α（Al） matrix of this alloy under DUV treatment. The tensile strengths of the samples at the room temperature and 573 K are 230 MPa and 145 MPa, respectively. The coefficient of thermal expansion （CTE） between 25 ℃ and 300 ℃ is 16.052 8×10^-6 ℃^-1, and the wear rate is 1.55%. The hardness of this alloy with 2% Fe reaches HB146.3. It is discovered that modified morphology and uniform distribution of the Fe-containing intermetallic compounds and the primary Si phase are the main reasons for reducing the CTE and increasing the wear resistance of this alloy.
文摘The work in this study is focused on the investigation of the structure and properties of ductile cast iron with nanoparticle additives： TiN （titanium nitride）, TiN ＋ TiCN （titanium carbonitride） and cBN （cubic boron nitride）. The nanoparticles are coated with nickel prior to addition to the iron melt to improve their wetting and uniform distribution in the volume of the casting. The metallographic observation and wear test are performed to study the influence of the nanoparticle additives on the microstructure and and cast iron tribological properties.
