Shin-ichi Matsuoka

Effects of extrusion conditions on microstructure and mechanical properties of AZ31B magnesium alloy extrusions

Abstract The effects of billet homogenization and extrusion conditions on microstructure and mechanical properties of AZ31B magnesium alloy extrusions is investigated. Mg–Al and Mg–Al–Zn compounds observed in the cast billet disappear with homogenization. Further, elongation of the extrusion increases with homogenization. As extrusion ratio increases, elongation of the extrusion also increases due to grain refining. When billet temperature is lower and extrusion speed is smaller, grain size of the extrusion decreases. As a result, the elongation of the extrusion increases.

Ultrasonic welding of ceramics/metals using inserts

Abstract This paper gives a description of an experimental study of the ultrasonic welding of ceramics and metals using inserts. Ultrasonic welding has made it possible to weld various ceramics such as Al 2 O 3 , SiC, Si 3 N 4 , AlN, to metals at room temperature, quickly and easily compared to other welding methods. For example, the ultrasonic welding of Si 3 N 4 /Al/Cu can be accomplished under the conditions of: amplitude of ultrasonic horn top, 23 μm; welding pressure, 20 MPa; and required duration, 1 s. The ultrasonic-welding technique can be carried out in many different ways, such as the direct welding of ceramics/metals, welding with a metal coating on the ceramics surface by vacuum deposition and welding with a metal insert. The insert material and the vaporized film used for auxiliary purposes play the role of binders to facilitate welding, but little difference in welding strength was found between the welds with the metal insert and the vaporized film. Since ultrasonic vibration cleans the contact surface, there is no need to carry out surface treatment prior to welding.

Ultrasonic welding of ceramic/metal

Abstract This paper gives a description of an experimental study of the ultrasonic welding of ceramics and metals. Ultrasonic welding has made possible the welding of various ceramics, such as Al2O3, SiO2, ZrO2, SiC, and Si3N4, to aluminium and copper at the room temperature, both quickly and easily when compared to other welding methods. For example, the ultrasonic welding of Al2O3 and aluminium can be accomplished under the conditions of amplitude of ultrasonic horn top 23 μm, welding pressure 20 MPa, at a required duration of 0.3 s. The ultrasonic-welding technique can be carried out in many different ways, such as in direct welding of ceramics and metals, in the coating of metals on to a ceramics surface by vacuum deposition, and in applications involving the insertion of activated metals. When cleaned with forced ultrasonic vibration, the contact surfaces need no further surface treatment. Moreover, the material can be processed easily, the operation produces little heat, and there is virtually no resultant weakness of the product.

Ultrasonic welding and characteristics of glass-fiber reinforced plastic: comparison between the paper-making method and the impregnation method

Abstract The characteristics of glass-fiber reinforced plastic are influenced greatly by the type of matrix, the type or shape of the fiber and the method of reinforcement. For instance, the future of glass-fiber reinforced thermoplastic (GFRTP) as a practical material is noteworthy due to its wide range of elastic deformation and its strength, which latter is as great (weight for weight) as that of metal. As GFRTP has a wide application, an effective welding method is sought, for use along with conventional mechanical fastening and bonding methods. The basic research of the author on stampable sheet has established that the ultrasonic welding method is effective for GFRTP welding [1]. This paper reports on the possibilities of ultrasonic welding, on the characteristics of the joint strength and on the workability of the welded products. A comparison has been made between two kinds of fiber-reinforced plastic, produced by different manufacturing processes [2].

Effects of cold-rolling on the cold forging of solid polymer

Abstract Cold-forged products obtained from preliminarily-rolled rods of HDPE, PP, POM, ABS and PVC were studied for their elastic and thermal recovery, and secular change of dimension over time. The optimum amount of reduction of area in rolling, and the effect of heat treatment, were made clear in order to attain the best qualities of cold-forged products. The cold-forged products obtained from preliminary-rolled rod were found to have extremely good dimensional stability when subjected to heat treatment in a boiling-water bath. This cold-forging process was applied to make small machine parts such as knobs, good results being obtained.

Effects of ultrasonic vibration on the compaction molding of polymeric powders

Abstract The ultrasonic molding technique has been developed for the purpose of producing products equivalent to conventional melted products in mechanical strength and structure, at high speed and high precision, without heating, by ultrasonic vibration only. By increasing the amplitude (2 a ) of the ultrasonic vibration and the compacting pressure and decreasing the powder weight, the minimum required duration time ( T min ) of ultrasonic vibration can be shortened, and in this connection an empirical equation T min · a n = F has been obtained. In these experiments, n = 1.7 (PA) to 2.0(HD?PE) approximately, PA and HD/PE referring to polyamide and high density polyethylene, respectively. The mechanical strength of ultrasonically molded products was found to be almost the same as that of conventionally melted products and, furthermore, the internal structure was free from orientation. The method uses powdered stock and can accomodate a wide range of materials: for example, thermosetting resins and high molecular materials that are not very fluid but are mechanically strong.

Effects of Manganese Contents on Extruded Magnesium Alloys

Effects of manganese contents in AZ31 and AZ10 on billets microstructure, extrusion loads, occurring of surface cracks and mechanical properties were investigated. In the range 0 to 0.8% manganese content, there exist an adequate manganese content for avoiding surface cracks and obtaining the highest tensile strength.

Characteristics About Thermal Insulation of High Temperature Type Vacuum Insulation Panel Using Soluble Polyimide

To comply with energy saving, vacuum insulation panels (VIP) have been used in low temperature application in some years now. And for more high temperature, the material composition and process of VIP were reviewed, the SUS foil was adopted as packaging material, and soluble polyimide was developed as the thermo compression bonding material for high temperature VIP at 150°C. To lower the glass-transition temperature (Tg) under 200°C for the thermo compression bonding (Max230°C), we elaborated the new soluble polyimide using aliphatic diamine copolymer, and controlled Tg to about 176°C. By making from trial VIP and evaluations, it was possible to be maintain high performance concerning coefficient of thermal conductivity : λ<8 [×10-3W/ (m·K)] at 150°C.