Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 3
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the results of tests concerning the effect of the extrusion process in the complex strain state on the microstructure and properties of one of magnesium alloy with aluminium, zinc and manganese, designated AZ61. Due to its specific gravity, it is increasingly being used in the automotive and aerospace industries to reduce the weight of structural elements. As a result of plastic deformation processes, rods with a diameter of 8, 6 and 4 mm were obtained from AZ61 magnesium alloy. The microstructure analysis was performed using light and electron microscopy (STEM) techniques in the initial state and after plastic deformation. Microstructure studies were supplemented with a quantitative analysis using the Metilo program. A number of stereological parameters were determined: average diameter of grain, shape factor. A static tensile test was carried out at 250ºC and 300ºC, at deformation rates of 0.01, 0.001 and 0.0001 m·s–1. Better plastic properties after deformation using KoBo method were obtained than with conventional extrusion.

Go to article

Authors and Affiliations

Iwona Bednarczyk
ORCID: ORCID
D. Kuc
A. Tomaszewska
M. Tkocz
Download PDF Download RIS Download Bibtex

Abstract

The article presents tests results of metalforming of magnesium alloy AZ61. Materials for tests were ingots sized  40×90 mm from magnesium alloy marked with symbol AZ61. Before the shaping process the ingots underwent heat treatment. As a result of conduction of the deformation processes there were rods achieved with diameter of 8 mm. There were axisymmetrical compression tests conducted on the samples taken from rods in temperature range from RT to 350ºC in order to determine the plasticity and formability of the alloy AZ61. Static tensile test was conducted in room temperature (RT), in 300ºC and in 350ºC. With the use of light and electron microscopy techniques the changes which occurred in the microstructure of AZ61alloy in initial condition and after plastic deformation (classic extrusion, KoBo method extrusion) were described. The deformation of alloy AZ61 using the KoBo method contributes to an increase in strength and plastic properties. The effect of superplastic flow was found at a temperature of 350ºC, where a 300% increase in plastic properties – elongation value was obtained. The analysis of the microstructure showed a significant grain size reduction in the microstructure of alloy AZ61 after deformation by the KoBo method and after an axisymmetric compression test, where grains of an average diameter of d = 13 µm were obtained.

Go to article

Authors and Affiliations

I. Bednarczyk
Download PDF Download RIS Download Bibtex

Abstract

Basing on experimental data, the possibility of consolidating side products of turning, milling and drilling of aluminum alloys into the form and properties of solids metals using low-temperature KoBo extrusion method has been assessed. Research regarding mechanical and structural properties of the final products revealed their total consolidation and proved their compatibility with requirements for products made of bulk billets. Importantly, the chips consolidation process does not require high or even raised temperature, which significantly reduces the unfavorable phenomenon of chips oxidation and its negative influence on the structure and mechanical properties of products. A very good effect of chips compaction has been proved by KoBo method, which has been confirmed by relatively slightly different mechanical properties of the material after recycling compared with the bulk one. Among currently applied techniques of consolidation of dispersed fractions in a solid state (leaving the melting stage out), the KoBo method seems an innovative way of utilizing metallic chips, as it enables a cold deformation process.

The paper presents investigations using 2024 and 7075 aluminum alloys chips from manufacturing process, formed into briquettes and deformed under conditions of KoBo extrusion process, which enables to obtain long product by cold forming. The final product characterized by good microstructures, mechanical features and low cost of production.

Go to article

Authors and Affiliations

B. Pawłowska
R.E. Śliwa
ORCID: ORCID
M. Zwolak
ORCID: ORCID

This page uses 'cookies'. Learn more