Micro‐Forming Using Ultrafine‐Grained Aluminum Processed by Equal‐Channel Angular Pressing

Abstract

A very high-purity (99.999%) aluminum was processed by equal-channel angular pressing (ECAP) at room temperature through 1 to 8 passes using a die with a channel angle of 90°. Analysis shows that processing by ECAP produces an ultrafine-grained (UFG) structure with a grain size of %1.3 mm and with microhardness and microstructural homogeneity. The mechanical properties and the fracture behavior were evaluated using micro-tensile testing after ECAP processing. A micro-forming process was used to fabricate a micro-turbine at ambient temperature and subsequent examination demonstrated that UFG pure aluminum gives higher strength and more uniform mechanical properties by comparison with conventional coarse-grained pure aluminum. The results confirm the very significant potential for using UFG pure aluminum for micro-forming at ambient temperature.

Developing ultrafine-grained materials with high strength and good ductility for micro-forming applications

“…Imposing a short term anneal of 10 minutes after the HPT processing has a significant effect on the microstructure and tensile properties of the HPT-processed specimens. There exists an optimum condition for the Al-1% Mg alloy by processing using HPT at room temperature and then giving the material a short anneal for 10 minutes at 423 K. Pure aluminium processed by ECAP to 8 passes produced materials with an average grain size of 1.3 m and this has been successfully applied to micro-forming of micro-turbine parts [17,18]. It was 07002-p. 5 reported that the geometries and surface quality of the compressed samples can be improved using UFG pure Al processed by ECAP through 8 passes by comparison with coarse-grained pure Al [18].…”

“…There is only limited research on the application of SPD processed materials in micro-forming [6,[15][16][17][18]. Therefore, experiments were conducted to investigate HPT processing of an Al-1% Mg alloy and to develop a processing route to improve the material ductility after SPD processing in order to attain a material suitable for micro-forming applications.…”

Micro-deformation behavior in micro-compression with high-purity aluminum processed by ECAP

“…For these experiments, the billets were sprayed with an MoS 2 lubricant and processed for 1, 2, 4 and 8 passes. Further details on ECAP processing are provided elsewhere [14].…”

An evaluation of formability using micro-embossing on an ultrafine-grained magnesium AZ31 alloy processed by high-pressure torsion

“…The UFG pure Al has been successfully applied to fabricate micro-turbine using micro-forming at room temperature [27]. The UFG AZ31 alloy processed by HPT through 5 turns with an average grain size of 200 nm has excellent formability during micro-embossing using the V-groove die.…”