Light weights wheels improve vehicle performance with respect to road handling, cornering as well providing fuel economy and reduced greenhouse gas emissions. Aluminum wheels are currently used in many models and are ...Light weights wheels improve vehicle performance with respect to road handling, cornering as well providing fuel economy and reduced greenhouse gas emissions. Aluminum wheels are currently used in many models and are produced usually by low pressure assisted gravity casting. Important property requirements are fatigue strength, pressure tightness, tensile strength, impact resistance, and corrosion resistance. Many attempts have been made to convert aluminum road wheels to magnesium. Race cars and some of the high end models (Porsche, Ferrari, etc.) have used magnesium wheels. These wheels have been gravity cast or forged. Viable corrosion protection systems have been developed and magnesium wheels have been used with success on these models. To use magnesium on more modest models is a challenge due to cost issues. Higher productivity casting processes or more cost effective coating systems need to be utilized. The project consists of selecting magnesium alloys for road wheels, examining the possible cost effective casting processes and corrosion protection systems, evaluating the cost per one wheel and comparing it to aluminum wheel costs. The wheels will also be compared with respect to fatigue and impact properties, pressure tightness, and corrosion.展开更多
Recently,MXenes have attracted considerable attention owing to their unique physical and chemical properties.Construction of MXenes to three-dimensional(3D)porous aerogel structures can play a critical role in realizi...Recently,MXenes have attracted considerable attention owing to their unique physical and chemical properties.Construction of MXenes to three-dimensional(3D)porous aerogel structures can play a critical role in realizing the profound implications of MXenes,especially for environmental remediation.Nevertheless,developing mechanically robust MXene-based aerogels with reversible compressibility under harsh conditions,such as liquid environments,remains challenging due to the insufficient interfacial strength between MXene nanosheets.Herein,3D porous MXene-based nanocomposite aerogels are developed by dual physical and chemical crosslinking strategy with poly(vinyl alcohol)and formaldehyde in this study.The developed MXenebased nanocomposite aerogels with designed interfacial engineering exhibit outstanding structural stability and extremely high reversible compressibility up to 98%strain as well as unprecedented mechanical durability(2000 cycles at 50%strain)in water environment.Moreover,the aerogels show adaptable compressibility when exposed to different solvents,which is explained with the Hansen solubility parameter.Thanks to their high compressibility in water,the robust MXene-based aerogels exhibit excellent methylene blue adsorption performance(adsorption capacity of 117.87 mg·g^(−1))and superior recycling efficiency(89.48%at the 3rd cycle).The porous MXene-based nanocomposite aerogels are also demonstrated with outstanding thermal insulation capability.Therefore,by synergistically taking their porous structure and super elasticity in liquid environment,the MXene-based aerogels show great promise in diverse applications including adsorption and separation,wastewater purification desalination,and thermal management.展开更多
文摘Light weights wheels improve vehicle performance with respect to road handling, cornering as well providing fuel economy and reduced greenhouse gas emissions. Aluminum wheels are currently used in many models and are produced usually by low pressure assisted gravity casting. Important property requirements are fatigue strength, pressure tightness, tensile strength, impact resistance, and corrosion resistance. Many attempts have been made to convert aluminum road wheels to magnesium. Race cars and some of the high end models (Porsche, Ferrari, etc.) have used magnesium wheels. These wheels have been gravity cast or forged. Viable corrosion protection systems have been developed and magnesium wheels have been used with success on these models. To use magnesium on more modest models is a challenge due to cost issues. Higher productivity casting processes or more cost effective coating systems need to be utilized. The project consists of selecting magnesium alloys for road wheels, examining the possible cost effective casting processes and corrosion protection systems, evaluating the cost per one wheel and comparing it to aluminum wheel costs. The wheels will also be compared with respect to fatigue and impact properties, pressure tightness, and corrosion.
基金the National Research Foundation of Korea(No.2022R1A2C3011968).
文摘Recently,MXenes have attracted considerable attention owing to their unique physical and chemical properties.Construction of MXenes to three-dimensional(3D)porous aerogel structures can play a critical role in realizing the profound implications of MXenes,especially for environmental remediation.Nevertheless,developing mechanically robust MXene-based aerogels with reversible compressibility under harsh conditions,such as liquid environments,remains challenging due to the insufficient interfacial strength between MXene nanosheets.Herein,3D porous MXene-based nanocomposite aerogels are developed by dual physical and chemical crosslinking strategy with poly(vinyl alcohol)and formaldehyde in this study.The developed MXenebased nanocomposite aerogels with designed interfacial engineering exhibit outstanding structural stability and extremely high reversible compressibility up to 98%strain as well as unprecedented mechanical durability(2000 cycles at 50%strain)in water environment.Moreover,the aerogels show adaptable compressibility when exposed to different solvents,which is explained with the Hansen solubility parameter.Thanks to their high compressibility in water,the robust MXene-based aerogels exhibit excellent methylene blue adsorption performance(adsorption capacity of 117.87 mg·g^(−1))and superior recycling efficiency(89.48%at the 3rd cycle).The porous MXene-based nanocomposite aerogels are also demonstrated with outstanding thermal insulation capability.Therefore,by synergistically taking their porous structure and super elasticity in liquid environment,the MXene-based aerogels show great promise in diverse applications including adsorption and separation,wastewater purification desalination,and thermal management.