Fatigue Crack Growth and Related Microstructure Evolution in Ultrafine Grain Copper Processed by ECAP

Mechanical Properties and Microstructure Development of Ultrafine-grained Cu Processed by ECAP

Technical purity Cu (99.95 wt%) polycrystals have been processed at room temperature by equal channel angular pressing. The results of mechanical tests and the microstructure characterization by various experimental techniques are presented. The yield stress as well as the strength were shown to increase with increasing strain and exceed the respective values of a coarse-grained material. The m...

Microstructure of Ultrafine- Grained Metals after Ecap

This paper was aimed at verification of functionality of the ECAP technology at extrusion of the copper, alluminium alloys and steel. Experiments were made on equipment, which is demonstrated in the Fig 1. Deformation forces were measured during extrusion, resistance to deformation was calculated and deformation speed was determined approximately. Analysis of structure was made with use of ligh...

Microstructure evolution and abnormal grain growth during copper wafer bonding

Evolution of microstructure morphologies and grain orientations of Cu-Cu bonded wafers during bonding and annealing were studied by means of transmission electron microscopy, electron diffraction and X-ray diffraction. The bonded Cu grain structure reaches steady state after post-bonding anneal. An abnormal (220) grain growth was observed during the initial bonding process. Upon annealing, the ...

Fatigue Crack Resistance of Ultrafine-Grained Copper Structures

Microstructure Evolution in High Purity Aluminum Single Crystal Processed by Equal Channel Angular Pressing (ECAP)

Aluminum single crystal with 99.999% purity was deformed at room temperature by equal channel angular pressing (ECAP) up to 16 passes. Grain size and misorientation of processed samples were quantitatively characterized by TEM and EBSD. The results show that the refinement efficiency of high purity aluminum single crystal was poor in the initial stage. Extrusion by fewer ECAP passes (n ≤ 8) res...