Manufacturing of Open-Cell Zn-22Al-2Cu Alloy Foams by a Centrifugal-Replication Process
- PDF / 2,924,618 Bytes
- 10 Pages / 593.972 x 792 pts Page_size
- 11 Downloads / 184 Views
UCTION
METAL foams have emerged as an important field of research due to their special structure for impact energy absorbing and low weight, particularly aluminum alloy foams. Metal foam application generally depends on its macroscopic structure (pore size, pore morphology, overall porosity, and distribution) as well as the alloy’s inherent properties (yield strength, Young’s modulus, and hardness).[1] The interest in the practical applications of foamed metals drives the development of several methods to manufacture metallic foams from aluminum alloys. Among them, a simple and versatile method is the replication process, where the liquid metal is infiltrated through the pre-existing network of a leachable preform. One of the attractive features of the replication process is the high degree of control in the size and shape of the pore.[2] The preform is usually comprised of NaCl particles, which result in the formation of a porous structure once the metal
A. SA´NCHEZ, A. CRUZ, J.E. RIVERA, and J.A. ROMERO are with the Instituto Polite´cnico Nacional - ESIQIE, UPALM Zacatenco, 07051, Ciudad de Mexico, Mexico and also with the Departamento de Ingenierı´ a en Metalurgia y Materiales, Instituto Polite´cnico Nacional Escuela Superior de Ingenierı´ a Quı´ mica e Industrias Extractivas (ESIQIE), UPALM, 07738, Mexico D.F., Mexico. Contact e-mail: [email protected] M.A. SUA´REZ and V.H. GUTIE´RREZ are with the Instituto Polite´cnico Nacional - UPIIZ, Blvd. del Bote s/n, ejido la Escondida cerro del gato, Ciudad Administrativa, 98160, Zacatecas, Mexico. Manuscript submitted December 6, 2016. Article published online November 21, 2017 272—VOLUME 49A, JANUARY 2018
solidifies and after leaching of the preform. NaCl particles are widely used to produce open-cell foams because of their high degree of control in the size and shape of the pore, high melting point, and nonchemical reaction with the alloy. The driving of the liquid metal into the spaces left by the preform requests the application of pressure on the metal, since the metal does not infiltrate spontaneously because liquid metals usually do not wet the interstitial spaces of the preform.[3] This application of pressure or driving force for the infiltration of liquid metal into a porous material can be generated several ways, such as by vacuum-assisted pressure, gas pressure, and extrusion pressure.[4–6] Nowadays, most researchers have focused their work on foaming aluminum alloys[6,7]; the basic principles of foaming technology have been transferred to other low-melting metals, especially in Zn-Al alloys since they exhibit good capacity to absorb energy and mechanical damping. Zinc and its alloys have a lower melting point than aluminum alloys, and they have compatibility with steel regarding corrosion resistance, which could be suitable for filling hollow steel sections to improve their stiffness.[8] Kitazono and Takigushi[9] pointed out that in the case of metallic materials, an increase in strain rate sensitivity (m) is desirable for energy absorbing materials. They repo
Data Loading...
