Surface motions due to a disbonding of stainless overlay from base metal has been measured by the use of a commercially available flat-frequency displacement transducer. The experimental result showed that a buried tensile crack (penny-shaped crack) can be generated by hydrogen-induced disbonding of stainless weld overlay from base metal. Acoustic emmission (AE) was found to be very sensitive and effective to monitor the disbonding. Some tens of AE events could be located by using two meaningful delta-t values. The detected waveforms due to the disbonding exhibited interesting variation as a function of the distance between the source epicenter and the transducer location. On the basis of the theory of elastodynamics and dislocation models, simulation analysis was made for surface motions due to a penny-shaped crack parallel to the stress-free surface in a half-space. Simulated waveforms were obtained as a function of the distance between the epicenter and the observation position. Comparison of the detected and simulated waveforms indicated remarkable agreement in the early time response. This excellent agreement demonstrates the applicability of the transducer and the present simulation analysis to quantitative waveform analysis relating to fundamental AE work. It is shown that quantitative analysis of microfracture due to the disbonding can be readily made by comparison of experimentally measured surface displacements and theoretically calculated surface motions.

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The methods of multiwall meteoroid protection for spacecraft have been developed through the Apollo Program. The bumper is shown to be the most important element because it remarkably reduces the damage from the debris impact on the mainwall. The fundamental impact test was carried out to obtain the design data for a dual element meteoroid shield structure using 4mm sphere pellets at velocity 4.1 to 4.8km/s. In all cases, thickness of the Al alloy (2024-T3) bumper and mainwall are 2mm and the distance between them is 170mm. As the first report, one method to separate the pellet of manganesezinc polycrystalline ferrite from the sabot at hypervelocity and its velocity measuring method which modifies a conventional magnetoflyer method are described in this paper.

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In the case of apparatus such as the Belt, high pressure is generated only by mechanical force. Since a large portion of a served thrust is wasted over the gasket, efficiency of pressure generation η (=pA/F, p: generated pressure, A: cross-sectional area of pressure medium, F: served thrust) is relatively low. A new method without the gasket is proposed in this paper. The beauty of the new method is utilization of a frictional force caused between the inner surface of the cylinder and the side surface of the spacer made of a ductile material. Thermal expansion of the pressure medium is restrained by combined action of the served thrust and the frictional force. Therefore, the required thrust decreases in proportion to the increase in the frictional force. It leads to the improvements in efficiency of pressure generation and probability of the pistion breakage. The frictional force increases with the increase in generated pressure, and attains to the maximum value confined by the shearing resistance of the material used for the spacer. The spacer further has an effect on relaxation of steep slope of inner pressure applied to the cylinder. This effect suppresses the occurrence of the horizontal crack.

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The HIP process was originally devised at Battelle Memorial Institute for diffusion bonding of nuclear fuel elements in the middle of 1950's. This innovative technique has been a subject of global research and development, and begun to be applied to cemented carbide industry at the end of 1960's by ASEA/Sandwick. Since then this process has been applied to the fabrication of many industrial materials including tool steel, superalloy, electronic materials and ceramics.
In Japan, the mass-production of HIPed alumina and cermet as cutting tool has started in 1974. In addition to this, HIP process was also applied to the commercial production of soft ferrite and piezo electronic ceramics.
The success of the above businesses has temptated the use of HIP process in the fabrication of other oxide and non-oxide ceramics as engineering materials, such as PSZ, Si₃N₄ and SiC. For example, HIPed PSZ ceramics can be used for engine components as well as knife, scissors, shoe-spikes, etc.
In recent years, the following new applications of HIP technique have been developed. They are: diffusion bonding between ceramics and between ceramics and metals, self-combustion reaction, plasma-sprayed ceramic coating on metal substrates. Among these, a new synthesis method of nitrides, such as Si₃N₄, AlN, TiN and NbN etc., by a combustion reaction under nitrogen pressures using HIP equipment is noted as an unique way to promote rapid formation of nitrides and to control the stoichiometry.

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As continued previous 1st paper, this paper describe various test and inspection method for pressure veseel according Japanese regulations mainly.
There are explained these test and inspection techniques on design, materials, and manufactureing.
Also, suggest some idea on total evaluation of these test results for quality and safety assurance of pressure Vessel.

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