Engineering Materials Vol II (microstructures processing design) 2nd ed - M Ashby D Jones (1999) WW Part 3 ppsx

... about 0.6 mm min −1 . At 30 °C the speed is 2 .3 mm min −1 . And the maximum growth speed, of 3. 7 mm min −1 , is obtained at an interface temperature of 24°C (see Fig. 6 .3) . At still lower temperatures ... good example to begin with is solidification – most metals are melted or solidi ed during manufacture, and we have already looked at two case studies involving solidi- fication (zone r...

Ngày tải lên: 11/08/2014, 02:22

... defect in the small volume subjected to the highest stresses is small. 18 .3 Modulus-of-rupture tests were done on samples of ceramic with dimensions l = 100 mm, b = d = 10 mm. The median value of ... metal such as molybdenum (usually applied as a powder and then heated). 200 Engineering Materials 2 Fig. 19.9. Forming methods for glass: pressing, rolling, float-moulding and blow-mouldin...

Ngày tải lên: 11/08/2014, 02:22

... necessitates a different design approach (Chapter 27). Most polymers are made from oil; the technology needed to make them from coal is still poorly developed. But one should not assume that dependence ... this chapter we examine three cement pastes: the primitive pozzolana; the widespread Portland cement; and the newer, and somewhat discredited, high-alumina cement. And we con- sider the pro...

Ngày tải lên: 11/08/2014, 02:22

... more demanding struc- tural applications, have design methods evolved. In designing with ductile materials, a safety-factor approach is used. Metals can be used under static loads within a small ... pin of a pin-jointed frame, made of metal, fits poorly, then the metal deforms locally, and the pin beds down, redistribut- ing the load. But if the pin and frame are made of a brittle material, ....

Ngày tải lên: 11/08/2014, 02:22

... solid. (c) Lead-rich solid only. (d) Liquid only. 2.6 (a) Liquid plus lead-rich solid between 1 and 2. (b) Lead-rich solid between 2 and 3. (c) Lead-rich solid plus tin-rich solid below 3 (see ... a branched shape called a dendrite. Many alloys show primary dendrites (Fig. A1 .34 ); and the eutectic, if it forms, fills in the gaps between the branches. 36 0 Engineering Materials 2 Pe...

Ngày tải lên: 11/08/2014, 02:22

... worked or heat-treated into finished products; and by understanding these, shape and size can, to a large extent, be predicted. Background reading M. F. Ashby and D. R. H. Jones, Engineering Materials ... removed impurity from the left-hand end of the bar and dumped it at the right- hand end; that is, we have zone refined the left-hand part of the bar. Because we need to know how lon...

Ngày tải lên: 13/08/2014, 05:20

... (wt%) s y (MPa) Slowly cooled Quenched and aged 2000 Al + 4 Cu + Mg, Si, Mn 130 465 6000 Al + 0.5 Mg 0.5 Si 85 210 7000 Al + 6 Zn + Mg, Cu, Mn 30 0 570 Work hardening Commercially pure aluminium (1000 ... equilibrium temperature. If, instead of using undersaturated ammonium chloride solution, we pour saturated solution into the mould, we get what is called “big-bang” nucleation. As the fresh...

Ngày tải lên: 13/08/2014, 05:20

... wear and tear. Untempered martensite is far too brittle for hammer heads. Having solved the immediate problem to our satisfaction we still wondered how the manufacturer had managed to harden the ... quenched and tempered state. In other words, “run- ning the temper” of a high-speed steel makes it harder, not softer; and tools made out of high-speed steel can be run at much higher cutting spee...

Ngày tải lên: 13/08/2014, 05:20