Effect of interfacial weight loss by silver migration on the pullout strength of a silver wire embedded in an adhesive matrix

In this study an effort is made to correlate interfacial weight loss, by migration, from the surface of a silver wire embedded in an adhesive matrix, to bond strength between the silver wire and the adhesive matrix. Comparative studies are also performed using an aluminum an wire in place of silver to accurately assess the effect of interfacial weight loss by silver migration. The results of the pullout tests on silver migrated specimens are compared with pullout tests on silver-wire specimens, which were immersed in water for 2 h but without silver migration. Pullout tests are performed in both wet, and dry conditions of the bonded specimens. It is determined that the pullout strength of bonded silver-wire specimens in wet condition decreases by as much as 86%, subsequent to silver migration. The loss of bond strength for silver-migrated specimens tested in dry condition varies between 23% and 4%, depending on the embedded length used.     

Pouring control with prediction of filling weight in tilting ladle type automatic pouring system

Abstract

This paper presents an advanced control system in a tilting ladle type automatic pouring system. To improve the productivity and save energy, in the pouring process, it is important that the mould be filled precisely and quickly with molten metal. A sequence control employing prediction of filling weight is proposed in this paper. In the proposed control system, the sequence parameter varies depending on the predicted filling weight during the back tilting. The proposed control system has an advantage in that it can be performed by common control equipment such as a programmable logical controller. The effectiveness of the proposed filling weight control system is demonstrated through the experiments using water.     

Mechanisms for the Improvement in Interfacial Adhesion Between UHMWPE Reinforcement and Nano-epoxy Resins with Reactive Graphitic Nanofibers

Previously developed nano-epoxy matrices with reduced viscosity showed both substantially enhanced mechanical properties and interfacial adhesion with ultra-high molecular weight polyethylene (UHMWPE) fibers vis-à-vis pure epoxy. In this work, mechanisms for the improvement in the interfacial adhesion were investigated. Atomic Force Microscopy and Energy Dispersive X-ray with Scanning Electron Microscopy analyses indicated that improved performance of the UHMWPE fiber composites with the nano-epoxy containing reactive graphitic nanofibers (r-GNFs) is attributed to mechanical interlocking and a diffusion mechanism. The nano-epoxy with the 'liquid nano-reinforcement' resulting in reduced viscosity provided better wettability, diffusion capability and reinforcing effect, which produced an effective improvement in the adhesion properties.     

Viscometric study of aqueous poly(vinyl alcohol) (PVA) solutions as a binder in adhesive formulations

Commercial grade poly(vinyl alcohol) (PVA) is widely used in adhesive and textile industries. The density and viscosity of an aqueous PVA solution are important properties in the various processing stages in these industries. In this work, the density and viscosity of aqueous PVA solutions are measured and the average molecular weight of PVA is determined. The measured densities are expressed by a simple linear equation in terms of PVA weight fractions. The coefficients of the density equation are calculated and presented. The measured viscosities are fitted to the modified Eyring viscosity model developed by the authors and the parameters of the model are evaluated. The viscosity model with known parameters for aqueous PVA solutions has the added advantages that it can be used in practical applications in various industries for predicting viscosity of aqueous PVA solutions without recourse to expensive and time consuming experimental measurements.     

Trends in automotive materials: state of steel and processing technologies and future tasks

Abstract

The average fuel consumption of Japanese vehicles is improving constantly and the material share of non-ferrous and non-metal materials is constantly evolving. There is too little general understanding of the role advanced steel products are playing in power train systems to improve fuel mileage. Future developments in automotive materials, and steel in particular, are considered.     

Velocity of elastic waves in porous ceramic materials: influence of pore structure

Abstract

A review has been undertaken of recently published data on ultrasonic velocity-porosity for a variety of porous ceramic materials, including information on pore structure. These experimental data have been compared with data calculated using a spheroidal pore model incorporating information on pore volume fraction, shape, and orientation. Good agreement is obtained between experimental and calculated values, especially when fractional porosity is less than about 0·25, even when a single 'effective' pore shape is employed in the calculation. The agreement improves if a different pore shape for each porosity level (point by point analysis) is used. The predictive ability of the spheroidal pore model is thus demonstrated.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

19—A STUDY OF NEEDLED FABRICS. PART VI: THE MEASUREMENT OF PUNCHING FORCE DURING NEEDLING

An account is given of an investigation in which a small needle board was fitted to the compression cage of an Instron Tensile Tester and used to measure the forces developed during the penetration of a web by needles. The punching speeds were much lower than those in a needling machine. The effects of web weight, type of fibre, fibre length and fineness, density, a reinforcing base fabric, and punching speed were studied.     

13—A STUDY OF THE PARAMETERS MEASURED IN THE WRINKLING OF WOOL IN A FIXED-DEFORMATION TEST

In wrinkling tests based on angular recovery from a fixed deformation, constraints imposed on the fibres by virtue of yarn or fabric construction are of secondary importance. When ageing effects have been eliminated, this results in similar wrinkle-ratings for all fabrics. Any performance differences subjectively assessed during wear arise from either fabric deformability or optical effects caused by differences in curvature.