Abstract: Provided an electronic device including a main body and a kit connected to the main body, and the main body includes a battery, a first motor, an electric wire connected to the battery, and a first controller connected to the electric wire, the kit includes a second motor supplied with power through the electric wire, an inverter connected to the second motor, and a second controller connected to the electric wire and configured to control driving of the inverter, and the second controller is configured to transmit information to the first controller through switching frequency control of the inverter and control a switching frequency of the inverter so that a current associated with the second motor is greater than zero in a section in which transmission of the information is performed.

Abstract: Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a Mg—Al composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

Abstract: Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a Mg—Al composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

Abstract: Provided is a method of manufacturing a grain-refined aluminum-zinc-magnesium-copper alloy sheet, including manufacturing an aluminum alloy sheet from an aluminum-zinc-magnesium-copper alloy melt by twin-roll strip casting, primarily rolling the aluminum alloy sheet manufactured in step 1, cold rolling the aluminum alloy sheet manufactured in step 2, and performing a heat treatment on the aluminum alloy sheet manufactured in step 3, thereby reducing processing time and cost by using twin-roll casting. Since grain refinement and homogenization of the sheet manufactured by the twin-roll casting are maximized by sequentially performing warm rolling, cold rolling, and a heat treatment on the sheet, elongation may be improved.

Abstract: Provided are a method of manufacturing an aluminum-zinc-based alloy sheet using twin-roll casting and an aluminum-zinc-based alloy sheet manufactured thereby. Specifically, a method of manufacturing an aluminum-zinc-based alloy sheet, including preparing a melt by melting elements corresponding to an aluminum alloy including 0.5 wt % to 10 wt % of zinc, inevitable impurities and aluminum as a balance (step 1); and twin-roll casting by introducing the melt prepared in step 1 between a pair of rotating cooling rolls (step 2), and an aluminum-zinc-based alloy sheet manufactured thereby are provided. The present invention may manufacture an aluminum-zinc-based alloy sheet, in which twin-roll casting is known to be difficult due to a wide solid-liquid coexistence region, by twin-roll casting by using cooling rolls having high thermal conductivity and controlling a reduction force by the rotational speed of the rolls.

Abstract: In a high strength and high electrical conductive nano crystalline grain multi-layer copper alloy sheet, a plurality of high strength and high electrical conductive nano crystalline grain multi-layer sheets manufactured by roll-bonding an oxygen free copper (OFC) alloy sheet and a deoxidized low-phosphorous copper (DLP) alloy sheet are plastically bonded by roll-bonding method so that an OFC alloy layer and a DLP alloy layer are alternated to each other to have electrical conductivity of 85 IACS (%) or more and tensile strength of 500 MPa or more.

Abstract: Provided is a method of manufacturing a grain-refined aluminum-zinc-magnesium-copper alloy sheet, including manufacturing an aluminum alloy sheet from an aluminum-zinc-magnesium-copper alloy melt by twin-roll strip casting, primarily rolling the aluminum alloy sheet manufactured in step 1, cold rolling the aluminum alloy sheet manufactured in step 2, and performing a heat treatment on the aluminum alloy sheet manufactured in step 3, thereby reducing processing time and cost by using twin-roll casting. Since grain refinement and homogenization of the sheet manufactured by the twin-roll casting are maximized by sequentially performing warm rolling, cold rolling, and a heat treatment on the sheet, elongation may be improved.

Abstract: Provided are a method of manufacturing an aluminum-zinc-based alloy sheet using twin-roll casting and an aluminum-zinc-based alloy sheet manufactured thereby. Specifically, a method of manufacturing an aluminum-zinc-based alloy sheet, including preparing a melt by melting elements corresponding to an aluminum alloy including 0.5 wt % to 10 wt % of zinc, inevitable impurities and aluminum as a balance (step 1); and twin-roll casting by introducing the melt prepared in step 1 between a pair of rotating cooling rolls (step 2), and an aluminum-zinc-based alloy sheet manufactured thereby are provided. The present invention may manufacture an aluminum-zinc-based alloy sheet, in which twin-roll casting is known to be difficult due to a wide solid-liquid coexistence region, by twin-roll casting by using cooling rolls having high thermal conductivity and controlling a reduction force by the rotational speed of the rolls.

Abstract: In a high strength and high electrical conductive nano crystalline grain multi-layer copper alloy sheet, a plurality of high strength and high electrical conductive nano crystalline grain multi-layer sheets manufactured by roll-bonding an oxygen free copper (OFC) alloy sheet and a deoxidized low-phosphorous copper (DLP) alloy sheet are plastically bonded by roll-bonding method so that an OFC alloy layer and a DLP alloy layer are alternated to each other to have electrical conductivity of 85 IACS (%) or more and tensile strength of 500 MPa or more.