E-Mail Newsletter

             Issued by the Asian TOP Panel, July 2007

           The Chinese Mechanical Engineering Society (CMES)
           The Institution of Engineers, Indonesia (PII)
           The Japan Society of Mechanical Engineers (JSME)
           The Korean Society of Mechanical Engineers (KSME)


    According to the agreement made in the 2nd Asian TOP Panel Meeting,
the ENGINEERING NEWS IN BRIEF (E-mail newsletter) has now been edited
by the CMES for the year 2007.



(1)Fast-Cooling Technique And Equipments Of Large-Size Aluminium Profile
    (Source: CMES)
(2)Performance Of Coated Diamonds In Different Metal Matrices (Source: CMES)
(3)New Technology Type In Cold Combined Extrusion-Parallel Extrusion
    (Source: CMES)
(4)How do we account for esmaller is strongerf (Source: JSME)
(5)Development of Drug Delivery System Using Shock Wavea (Source: JSME)
(6)Effect of Melt-mixing Conditions on Fracture Properties of Bioabsorbable
    HA/PLLA Composite Materials (Source: KSME)
(7)Detailed Measurement of Heat/Mass Transfer in a Rotating Equilateral Triangular     Channel with Smooth Walls (Source: KSME)
(8)Simultaneous Measurement of Velocity and Temperature Fields in Micro-Scale
    Flow and Its Application to Electrokinetic Flow (Source: KSME)


(1)Fast-Cooling Technique And Equipments Of Large-Size Aluminium Profile

   ZHANG Jun YANG He College of Materials Science and Engineering, Northwestern    Polytechnical University
   XIE Donggang HAN Bingtao China Heavy Machinery Research Institute,

The necessity of cooling quickly large-size aluminum profiles extruded is analyzed. Based on the typical large-size aluminium profiles cooling velocity curve, the technical requirements for the quench process of large size profiled aluminum profiles is put forward. On base of thermal conduction theory, equations to calculate the quantity of cooling medium for large-size aluminium profiles quench are gained. And the corresponding foundation for fast cooling is established. Several fast cooling methods in common use are introduced. The technical characteristics of air-water combined quench are analyzed. On the foundation of large-size aluminium profiles quench theoretic, the technical process route for large-size aluminium profiles air-water combined quench is also put forward. Further the new and effective air-water combined quench equipment is developed. The experiment is carried out on the new quench. Experiment shows that the theoretic foundation for large-size aluminium profiles fast cooling is correct and the technical process route is reliable. The new quench equipments are used in several large-size aluminium extrusion line, which makes it to greatly improve the quality of the large size aluminum profiles.


(2)Performance Of Coated Diamonds In Different Metal Matrices

    YU Yiqing LI Yuan XU Xipeng
    College of Mechanical Engineering and Automation, Huaqiao University

Eight metal-bonded diamond tooling materials are fabricated to evaluate the performance of coated diamonds in different metal matrices. The contribution of coatings to transverse rupture strength is assessed through three-point bending tests. Coupled with SEM and EDS analyses, the bonding between diamonds and metal matrix is revealed. The effects of coatings to the wear performance of diamond segments are studied through circular sawing of granite and in-process monitoring of cutting forces and power in sawing. It is found that the coatings are positive to the increased retention of bond matrix to diamonds. It is difficult to establish a specific relationship between the wear performance of the specimens and their transverse rupture strength if the bond system is different. However, the bonding among bond matrix components contributes more than the bonding between the bond matrix and diamonds. The performance of coatings depends not only on whether the matrix contains rare earth but also on the types of bond matrix.


(3)New Technology Type In Cold Combined Extrusion-Parallel Extrusion

    LU Xianfeng ZHANG Ruhua MIN Shuigen School of Mechanical & Eletrical
    Engineering, Nanchang University

The combined forward extrusion experiment research that can simultaneous extrude all gibbose platform and pole in once excursion of hydraulic press is for the plane-hook-commutator body in motors|one kind of multi- pole part with gibbose platform & joined principal part. The experiments has actualized successfully integral cold extrusion of the hook-commutator, and implemented the numerical simulation by computer soft super forge for the cold extrusion process. The result manifest that the every part of combined extrusion deformation process has 3 stages parallel|compression, extruding gibbose platform and then pole at one time. According to that a new concept of collateral extrusion or a new distortion form in combined extrusion is put forward, and expect to provide some gists or references for more development of cold extrusion technics theory and application.


(4)How do we account for esmaller is strongerf?

    Mitsutoshi KURODA, Yamagata University

Metals display a strong size-dependence of mechanical properties when they are deformed into the plastic range: generally we observe the behavior esmaller is strongerf. This effect has been very important for an increasing number of applications in high-performance structural materials and MEMS. This article introduces theoretical approaches for plasticity at the micron scale. It is emphasized that a crystal plasticity approach, which incorporates effects of the geometrically necessary dislocations, seems to be very efficient. But, we have not yet sufficiently understood how the geometrically necessary dislocations affect the mechanical properties. Accordingly, there are many important open issues and a number of doctrines surrounding the foundations of the theories. Some numerical examples, by current theoretical models, for typical micron scale plasticity problems are presented.


(5)Development of Drug Delivery System Using Shock Waves

    Masaaki TAMAGAWA, Graduate School of Life Science and Systems     Engineering,Kyushu Institute of Technology

This letter describes development of drug delivery system using shock waves. In this system, microcapsules including gas bubbles are flown in the blood vessel, and finally broken by shock induced microjet, then drug is reached to the affected part in the body as same as traditional DDS. This method is efficient way to transfer the drugs near the affected part in human body, because there are no thermal effects on the living tissue by using shock wave comparing with the ultrasonic method. For developing microcapsules including a gas bubble, the penetration force of microjet should be controlled by shock wave strength (power), wave form of pressure, and capsule geometry and material properties. Especially the mechanical properties of membrane and geometry of the membrane is important parameter for changing the penetration strength of microjet in the microcapsule. In this letter, to clarify the relation between the elasticity and the probability of disintegration of membrane by shock-induced microjet from a bubble, the fundamental design method of the microcapsules is proposed.


(6)Effect of Melt-mixing Conditions on Fracture Properties of Bioabsorbable
    HA/PLLA Composite Materials

    Sang-Dae Park, Deok-Bo Lee Medical Engineering Class, College of Medicine,
    Korea University

Effects of melt-mixing conditions on fracture properties of hydroxyapatite filled bioabsorbable poly(L-lactic acid)(HA/PLLA) composites was investigated by measuring the fracture toughness value of HA/PLLA composites prepared under different mixing time and rotor speed. The fracture surface morphology was also examined by profile measurement and scanning electron microscopies. It was found that the fracture toughness of HA/PLLA composites decreases due to decrease of ductile deformation of PLLA matrix and debonding of interfaces with increase of the rotor speed and mixing time. Effect of mixing process on neat PLLA was also assessed, and it was found that the fracture toughness of PLLA decreases due to disappearance of multiple craze formation and increase of defects. Such thermal and shear-stress degradation were found to be the primary mechanisms of the degradation of HA/PLLA composites during melt-mixing process.


(7)Detailed Measurement of Heat/Mass Transfer in a Rotating Equilateral Triangular     Channel with Smooth Walls

    Kyung Min Kim, Dong Hyun Lee, Hyung Hee Cho Yonsei University

The present study investigated the heat/mass transfer characteristics in an equilateral triangular channel simulating the leading edge cooling passage in gas turbine blade. Using naphthalene sublimation method and pressure measurement experiments, local mass (heat) transfer and pressure coefficients were obtained. The experiments were conducted with three rotating numbers between 0.0 and 0.1; two channel orientations of 0‹ (model A) and 30‹ (model B); the fixed Reynolds number of 10,000. The results showed that the channel rotation caused the heat transfer discrepancy between suction and pressure sides. Due to the secondary flow induced by Coriolis force, the high heat transfer appeared on the pressure side. When the channel orientation was 30‹ (model B), the secondary flow caused the more uniform heat transfer distribution among leading edge and inner wall on pressure side than that of the model A.


(8)Simultaneous Measurement of Velocity and Temperature Fields in Micro-Scale
    Flow and Its Application to Electrokinetic Flow

    Beomjoon Lee1), Songwan Jin2), Young Won Kim1), Jung Yul Yoo1)

    1) Seoul National University,
    2) University of California, San Francisco

In this paper, a technique of simultaneously measuring the velocity and the temperature in micro-scale flow is proposed. This method uses particle tracking velocimetry (PTV) for measuring the velocity and laser induced fluorescence (LIF) for measuring the temperature. To measure the accurate velocity and temperature, images for PTV and for LIF are separated by using two light sources and a shutter which is synchronized with a camera. By using only one camera, measurement system can be simplified and the error from complicate optical system can be minimized. Error analyses regarding the concentrations of fluorescent dye and particle and the light source fluctuation are also conducted. It is found that the error of the temperature and the velocity highly depends on the concentration of fluorescent particles which are used for PTV. This technique is applied to the simultaneous measurement of the velocity and the temperature in the electrokinetic flow. It is found that the velocity and temperature vary with the electric field strength and the concentration of electrolyte.


Editor : Tian Ruizhu
           The Dept. of Internationa Affairs
           Chinese Mechanical Engineering Society

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