Structure and properties of engineering materials (Fourth Edition)

204 and nature of the examples but, with the exception of cams and gears, thereby to influence the content of the text itself. To take one example only, six different methods are described for finding velocity and acceleration in linkages, many of which are now quite uncompetitive, but nevertheless lead to suitable examination questions. There is a good case for learning t w o ways of doing things, one a quick, simple spot check; the other powerful, fast and fully computerised. The fact that it is difficult to assess understanding of the latter in an examination should not be a deterrent. We must devise ways to meet this problem, and incidentally thereby to release more time for the decisions that must be made before and after such computations. The prospective purchaser should perhaps be warned that this new SI version of the 3rd edition differs in only minor ways from the 3rd edition published in 1975. That 1975 edition itself was almost entirely in SI units. The main change in this new version is that metric gears are included. The b o o k has two parts: part one, on mechanisms, has chapters with the following headings; introduction, linkages, cams, spur gears, non-standard spur gears, bevel helical and worm gears, gear trains, computing mechanisms, introduction to synthesis. Part two, entitled dynamics of machinery, has chapters on kinematics of machinery, force analysis of machinery, balance of machinery, vibration in machines. TREVOR DAVIES

Structure and Properties of Engineering Materials (Fourth Edition), by R.M. Brick, A.W. Pense and R.B. Gordon. ISBN 07-007721-5, McGraw-Hill, Maidenhead, 1 9 7 7 . 5 1 2 pp., 67/16in by 91A in, hardback £18.75. I.S.E. £7.85. This edition of the book, formerly entitled "Structure and Properties of Alloys" aims to apply the basic approach of Physical Metallurgy to alloys, ceramics and polymers at an introductory level for engineers. The authors have had to delete parts of earlier editions in order to broaden the scope. This has made the task of writing such a basic b o o k even more difficult and the choice of what to exclude is inevitably subjective. The first six chapters deal with the basic concepts of Physical Metallurgy, dealing in turn with the structure and properties of metals, strengthening mechanisms in single phase and complex alloys. These chapters introduce phase diagrams and choose particular examples of alloy systems to illustrate the various strengthening mechanisms and heat treatment procedures. The following ten chapters cover the major industrial ferrous and nonferrous alloys; copper and copper alloys, aluminium alloys, magnesium and beryllium, titanium and zirconium, iron and steel, including tool steels and stainless steels, cast-irons and metals for high temperature use, are all discussed in these ten chapters. The final chapters deal, very briefly, with engineering polymers and ceramics. Four appendices cover metallography, failure of materials, splat

205 cooling and metal glasses, and a selection of phase diagrams. Thus a vast range of topics is covered in only about 500 pages. The level is explicitly introductory and the authors have generally managed to cover this wide range of topics at a satisfactorily uniform level. However, the discussion of some aspects seem to me too superficial to provide the basic knowledge to understand subsequent chapters. This criticism is especially true for the comments on page 8 concerning Miller indices which are misleading, and the very brief allusion to dislocations on page 72 and 73. The bowing of dislocations around particles, shown in Fig. 5.2, can hardly be meaningful to readers who have had only edge dislocations discussed very briefly (with a f o o t n o t e implying screw dislocations are important only in b.c.c, metals). Similarly, the brief discussion on twinning (which is said n o t to involve slip), on electron microscopy (where voltages of 150 V, 10kV and 50 kV are mentioned with a typical foil thickness of 100 A !) and on ordering where the section on page 67 is incomprehensible, highlight the difficulty of writing such a broad-based book. There are other criticisms, such as a confusion between weight and density on page 38 and an erratic use of brackets around crystal planes and directions. Units such as p.s.i, are intermixed with kg/mm 2 . Despite these shortcomings, I think many engineers may find it a useful book but it is certainly too superficial for a serious student of metallurgy. M.H. LORETTO

Manufacturing Processes, by A.D. Roberts and S.C. Lapidge. ISBN 07053151-X, McGraw-Hill, Maidenhead, 1977. 454 pp., hardback £13.45. This book gives a non-mathematical appraisal of manufacturing processes, presenting a broad examination of a wide number of processes, being comprehensive and w i t h o u t analytical depth. In general, the book is extremely well illustrated both with explicit diagrams and with photographs of industrial processes. Two other useful features are included: at the end of each chapter a set of review questions and problems are included which could be useful both to student and lecturer, and at the end of the book a set of appendices covering steelmaking, coding systems for metals, welding symbols and machining data make a useful addidtion. The opening chapters provide essential pre-requisites to the processes in the form of basic metallurgy, measuring equipment, quality control, tolerancing, dimensioning and the basics of machining. The illustrations are profuse and explicit and would be of considerable value to technicians doing laboratory-based engineering courses. A useful account of numerical control is then given, establishing fairly early in the book the importance of this technique in modern manufacturing. The next chapters are devoted to acquainting the reader with hardware in