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Water-lubricated bearings can significantly reduce the pollution to environment because the traditional oil lubricant is replaced by water in the bearings. The ultrahigh molecular weight polyethylene (UHMWPE) has proven to be effective and reliable for the manufacturing of water-lubricated bearings. However, limited work has been done to address the improvement of the tribological performance of the UHMWPE-based water-lubricated bearings using surface texture processing. This paper aims to investigate the effects of bar-grooved surface on the tribological performance improvement of UHMWPE-based water-lubricated bearings.

For the first time, the bar grooves were processed on the surfaces of UHMWPE-based water-lubricated bearings. The CBZ-1 friction and wear tester have been used to test the wear and friction performance of the bearing samples. The LI laser interference surface contour graph and the digital microscope have been used to measure the surface morphology of the specimens. The tribological characteristics of the tested bearings were analyzed.

With bar grooves added on the surfaces of the specimens, the friction coefficient of the specimens were lower than that of the specimens without surface texture processing; the wear quantity of the two kinds of specimens were almost the same; by using the LI laser interference surface contour graph and the digital microscope to measure the surface morphology of the specimens, the furrows of the specimens with bar grooves were narrower and shallower than that of the specimens without bar grooves.

The paper implicates that the surface texture processing using bar grooves can reduce the friction coefficient and prolong the service life of the water-lubricated bearings in practical applications.

This paper fulfills an identified need to provide important theoretical and experimental support to the design of water-lubricated bearings in practical applications.

The great fluidity of titanium metal in the molten condition lends itself to fusion welding without the addition of filler metal. The resulting welds are flush with the base metal and have high ductility, comparable to the ductility of the base metal. The welded joints can be made by hand or automatic methods. A critical requirement of this type of weld is fit‐up of the parts to be joined. The back‐up and hold‐down fixtures also have a decided effect on the resulting weld. A sheared surface resulting in a joint without gaps is required for a satisfactory weld. Fused welds have been principally used, to date, for longitudinal tight butt joints in material up to .062 in. thick. Further testing and experience should extend the limits of application. Bend tests made on welded samples have bent 180 deg. over a 2T bend radius exhibiting equal or greater ductility than the base metal. Welds tested in tension have exhibited over 100 per cent efficiency in all cases. The elimination of welding rod has reduced the amount of contamination in the weld and the weld area.

Flow structure and convective heat transfer in a plane channel with in‐line mounted rectangular bars have been investigated for different bar sizes in the Reynolds number range corresponding to steady laminar flow to unsteady transitional flow. Numerical results are reported for the thermal entrance region with six in‐line mounted bars and for the case with spatially periodic mounted bars. Data for heat transfer and pressure drop are presented for 100≤Re≤1,000 and bar heights 0.24≤d/H≤0.48. The unsteady Navier‐Stokes equations and the energy equation have been solved by a finite‐volume code with staggered grids combined with SIMPLEC pressure correction. Flow and heat transfer characteristics in the different rows are strongly dependent on Re and d/H. The flow structure and temperature field around the sixth row are compared qualitatively well with those calculated with periodic boundary conditions, however, the comparison of mean Nusselt number and friction factor shows differences for high Reynolds numbers.

SINCE their introduction into this country a few years ago, the inert‐gas‐shielded welding processes have rapidly become preeminent in the light‐alloy field, where their advantages are well known. At the Luton Establishment of Messrs D. Napier and Son, Ltd., these processes have been the subject of intensive development during the last three years, and this work has made possible their current adoption in various forms as normal productive processes. Wherever possible, mechanization has been introduced for reasons discussed later, and components are being produced in a variety of light alloys. The majority of the applications are highly stressed fabrications whose physical soundness and dimensional accuracy require to be of a particularly high standard.

This paper aims to improve the wear resistance of metal rubber microfilaments and the service life. The effect of surface texture by laser processing on the fretting friction properties of metal rubber microfilaments was studied.

The LQL-F20A laser marking machine was used to fabricate a ring groove array with equal spacing and dense arrangement on the surface of metal rubber microfilaments. The test was carried out with a self-made micro-dynamic frictional tester. The topography of the microfilaments was observed by scanning electron microscopy and analyzed.

It has shown that laser surface texturing can improve the wear performance of microfilaments. Under the same experimental conditions, the microfilaments of textured surface has a smaller depth of wear than un-textured specimen. The wear resistance increases with the increase of texture density. The friction coefficient of textured specimen is significantly reduced compared with un-textured specimen, and the surface texture density of microfilaments has little influence on the friction coefficient after stabilization. In the stage of stable fretting wear, the wear depth will be more with the increase of the load.

There is little research on metal rubber microfilaments tribological properties. In this paper, the effect of laser texturing of microfilaments on micro-dynamic friction properties was studied by friction machine to provide a reference for the application of metal rubber in aerospace, medical and other fields.

The purpose of this study is to investigate the effect of engineered micro-structures on the tribological properties of metal-polyetheretherketone (PEEK) surface.

Circular dimples with diameters of 25 and 50 µm were designed and manufactured on PEEK plate specimens using picosecond laser. Reciprocating friction and wear tests on a ball-on-flat configuration were performed to evaluate the tribological properties of the designed micro-structures in dry contacts. The loading forces of 0.9 and 3 N were applied.

As a result, obvious fluctuations of coefficient of friction curve were observed in tribosystems consisting of non-textured and textured PEEK with circular dimples of 25 µm in diameter. GCr15 ball/textured PEEK plate specimens with circular dimples of 50 µm in diameter revealed a superior friction and wear property.

Different to the existing studies in which the tribopairs consist of hard bearing couples, this study investigated the tribological properties of the engineered micro-structures on the hard-on-soft bearing couples.

A FACTOR which all industrialised countries must take into account is the general increase in the age of the world population. There are many reasons for this increase but one or two are self‐evident. There has been a spectacular drop in infant mortality. The fight against disease is progressively successful. Better living standards make for a sense of well‐being in the population.

The first edition of this book was published in 1947, and dealt almost exclusively with the design and operation of low‐speed wind tunnels. In the present edition much of the original material has been revised and brought up to date, and additional chapters have been added to extend the description to wind‐tunnel testing at high subsonic, transonic, supersonic, and hypersonic speeds. The growing importance of rotary‐winged aircraft has led to the inclusion also of a short chapter on the testing of helicopter rotors.

Words like Participation tend to be labels stuck on generalities, signifying nothing. They are used as verbal bromides by publicists anxious to cover harsh realities with an attractive veneer. As a rule, once they have served their purpose, they are conveniently forgotten.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued