China
Africa
Explore chapters and articles related to this topic
Flexible Films
Published in Martin W. Jawitz, Michael J. Jawitz, Materials for Rigid and Flexible Printed Wiring Boards, 2018
Martin W. Jawitz, Michael J. Jawitz
Rolled foils are different in every way from ED copper. This foil is very flexible and should be used in dynamic applications that require constant flexing. RA copper is manufactured by melting the cathode copper (which is produced electrolytically) and then formed into large ingots. This direct chill casting method allows for controlled solidification that provides continuous purity, monitoring, and grain size selection and also eliminates existing defects such as voids that would influence the quality of the foil when it is rolled into the final form. Because this process starts with copper ingots and has longer production cycles with incremental approaches to the final thickness, rolling results in a foil with horizontal grain orientation and smooth surfaces on both sides. Roll reduction quickly causes work hardening, with the result that rolled foils must be periodically annealed. They are sold in several degrees of hardness from “as rolled” to dead “soft.” Rolled annealed is the standard anneal condition that provides good flexural endurance and resistance to fracturing in dynamic use, which is typical of flexible printed wiring boards.
Physical and Mechanical Properties of Recycled Metal Matrix Composites
Published in R.A. Ilyas, S.M. Sapuan, Emin Bayraktar, Recycling of Plastics, Metals, and Their Composites, 2021
Pradeepkumar Krishnan, Ramanathan Arunachalam
Direct-chill casting (DC) is a primary industrial semi-continuous casting method for partially finished products. The partially finished products are further processed by either rolling, forging or extrusion. The DC casting mold has holes arranged along its bottom end, through which jets of water flow, forming an outer surface like a mold for direct chilling and solidification (Al-Helal et al., 2020). A simple schematic diagram of the direct-chill casting method is shown in Figure 8.3.
A review on development and applications of element-free galerkin methods in computational fluid dynamics
Published in International Journal for Computational Methods in Engineering Science and Mechanics, 2020
Wah Yen Tey, Yutaka Asako, Khai Ching Ng, Wei-Haur Lam
Singh [51], Singh and Tanaka [67] and Singh et al. [58, 185] applied the classical EFG to solve heat equation. Yang and He [71] expanded to study by considering the effect of temperature field to the phase change while Pham [63] considered the effect of a moving heat source on problem domain. Heat conduction on anisotropic material and direct chill casting processes was studied too by Zhang et al. [78] and Álvarez et al. [90] respectively. In these studies, K1, K2, u and can be defined as coefficient of thermal conductivity, volumetric heat capacity, field temperature, rate of internal heat generation respectively. Heat equation has been solved too using its variants comprising IEFG [113–115, 117, 118], SBEFG [149, 186], IEFG-SBEFG hybrid scheme [144] and MKEFG [179].
Fracture toughness of cast and extruded Al6061/15%Al2O3p metal matrix composites
Published in Australian Journal of Mechanical Engineering, 2020
H. A. Hassan, A. K. Hellier, A. G. Crosky, J. J. Lewandowski
The first set of materials tested was a cast and extruded aluminium alloy 6061 as well as 6061 reinforced with 15% by volume of Al2O3 particulate of average size 13 μm (Klimowicz and Vecchio 1990; Liu and Lewandowski 1993b). The 6061 composites were originally processed by Dural Aluminum Composites Corporation (DACC), San Diego, CA via proprietary molten metal and mixing technology. Direct chill-casting techniques were used to create 18 cm diameter × 110 cm long billets, with details provided elsewhere (Klimowicz and Nguyen-Dinh 1989). Table 1 gives the chemical composition of the unreinforced aluminium matrix alloy. The cast billets were cut to 45 cm lengths followed by forward extrusion using a 3850 ton hydraulic press with a bore diameter of 21 cm. Billet temperatures were 343–357 °C, with extrusion exit speeds of 13 m/min. The composite materials were received as 0.5 m long extrusions with 19 × 76 mm rectangular cross section. A 3-D optical metallographic view of the composite is provided in Figure 1. L is the length direction; T is the transverse direction; and S is the short transverse direction. At this magnification, it is clear that the reinforcement is somewhat banded, with preferential alignment of the particulate along the extrusion direction. No residual casting porosity was detected after such extrusion, consistent with previous work (Klimowicz and Vecchio 1990; Liu and Lewandowski 1993b).
Effects of scandium on hypoeutectic aluminium copper microstructures under low solidification rate conditions
Published in Canadian Metallurgical Quarterly, 2018
A.-A. Bogno, J. Valloton, H. Henein, D. G. Ivey, A. J. Locock, M. Gallerneault
Owing to the restricted availability and high cost of Sc, it would be beneficial to minimise the amount of Sc needed to achieve significant grain refinement. Thus, our aim is to study the effect of hypoeutectic Sc compositions (<0.55 wt-% Sc) on age-hardenable Al–Cu alloys under various solidification conditions in order to understand the effects of cooling/solidification rates. The objective of this paper, the first of two parts, is to analyse the effect of Sc in the hypoeutectic composition range for Al-4.5 wt-% Cu solidified under low solidification rate conditions comparable to processes such as direct chill casting.