Search results

A CRITICAL stage in the process of making aircraft occurs with alarming frequency in the history of aviation.

Some of the physical and intellectual requirements for management have been outlined, and in table ii, para 3.20, some generally agreed qualities are listed. Items 1 to 3 are individual and are not easily altered, certainly not at later stages in a career.

5.31. There are two primary kinds of knowledge. The first includes all that class which is instinctive, intuitive, or accepted as a fact of authority (i.e. one which really arises from an act of faith).

The purpose of this paper is to study how cryogenic CO₂ cooling during the welding process affects corrosion behaviour of friction stir welding (FSW) AA7010‐T7651.

Friction stir welded AA7010‐T7651 was produced with a rotation speed of 288 rpm and a travel speed of 58 mm/min. The liquid CO₂ was sprayed onto the weld centre line immediately after the toolpiece. The microstructures of welds in different regions were observed using Field Emission Gun Scanning Electron Microscope (FEG‐SEM). The effect on the corrosion susceptibility was investigated using a gel visualisation test and potentiodynamic polarisation measurements using a micro‐electrochemical technique.

The main corrosion region for both FSWs AA7010‐T7651 produced with and without cryogenic CO₂ cooling is in the HAZ region, which exhibited intergranular attack. Cryogenic cooling does not show any influence on anodic reactivity of the weld region (both nugget and HAZ) compared to uncooled weld metal. However, the width of the reactive HAZ is reduced after cooling, as compared to the uncooled weld. The cooled welds show higher cathodic reactivity in the nugget region than does the nugget region of uncooled welds.

There has been no previous work to investigate the effect of cryogenic CO₂ cooling on the corrosion behaviour of FSW AA7010‐T7651. The paper relates the microstructures of both uncooled and cooled welds to their anodic and cathodic reactivities using a micro‐electrochemical technique.

The Food Hygiene (General) Regulations, 1970, when they first appeared, seem to have attracted more notice in the daily press than in the specialist journals, although, while re‐enacting much that was in the 1960 regulations, which they repeal, the new measures break new and important ground, as well as introducing a number of amending provisions, which experience has shown were needed. We tend to associate hygiene needs of food and drink with the thronging streets of the city and town, the hidden backrooms of restaurants, the bustling market and the mobile food van, which, in this motorized age, has ousted the bawling backstreet hucksterer.

6.01. The borderline between an art and a science can be a narrow one. In an over‐simplified description it might be defined in terms of the content which is susceptible to measurement by standard and objective means. Most arts have some theory and in them some things which can be measured. Nearly all sciences have a region wherein success is only attained by exercising skill in the art and where no predetermined answer can be got by theory and measurements alone. It can be stated that the conversion of the complex subjects of management or production engineering into sciences depends to a great extent on the use of measurements which will ultimately serve as the raw material for theories or laws. The term ‘scientific management’, when first used, was certainly premature. What should have been suggested is that scientific methods were being used to convert arts into sciences. Even now, after some forty years of development there is some doubt whether the term is not ambitious and a little boastful. But there are clear signs that, in the best cases, the content of art is diminishing to a point where it can reasonably be considered to be the junior partner.

Armstrong Siddeley Motors Ltd., of Coventry, announce that Mr W. F. Saxton, chief engineer, has been appointed a director of the Company.

In previous divisions of this series, consideration has been given to a number of subjects which are individually parts of the process, or background, of Administration, Management and Production Engineering. This has been done without dealing exhaustively with each of them or with the prerequisite knowledge of other basic sciences needed for their understanding. Enough has been said, however, to indicate that, ideally, a wide field of knowledge should be available in a manager.

THIS is the first of a scries of articles on the broad subject of Production Engineering. Its object is to introduce and to explain the framework of the subsequent parts; to clear up some current misunderstandings, and to define the scope of the subject. The whole field will be reviewed briefly, not in a highly technical manner but for the practising aeronautical engineer regardless of his specialization; but it is hoped that even those who have an expert knowledge of many of the subjects included in this review will find some clarifications and some ideas which will be useful in their work.

SI Units constitute an internationally agreed measuring system which we, and the rest of the world will use increasingly from now on. The author describes these units and continues with some specialised ones in use in Tribolgoy. He shows how a problem in Tribology is worked out in a fraction of the time that would be taken if using Imperial calculations.