scholarly journals Increasing the Lightweight Potential of Composite Cold Forging by Utilizing Magnesium and Granular Cores

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
Robin Gitschel ◽  
Felix Kolpak ◽  
Oliver Hering ◽  
A. Erman Tekkaya
Keyword(s):  
Magnesium Alloy ◽  
Granular Media ◽  
Az31 Alloy ◽  
Cold Forging ◽  
Forming Limit ◽  
Process Route ◽  
Wide Range ◽  
Shear Yield ◽  
Magnesium Az31 ◽  
Hollow Shafts

In this paper a process sequence, that uses forward rod extrusion with cold forged C15 steel cup billets to produce lightweight shafts, is presented. The steel cup billets feature either a lightweight magnesium alloy core or a granular medium core that is removed after forming to obtain hollow shafts without the need of complex tools and highly loaded mandrels. It is shown that composite shafts featuring magnesium cores can be produced for a wide range of extrusion strains. Due to high hydrostic pressures in forward rod extrusion, the forming limit of magnesium at room temperature can be expanded. The observed bond strength between core and sheath is below the shear yield strength of utilized magnesium AZ31 alloy. Hollow shafts are successfully produced with the presented process route by utilizing zirconium oxide beads or quartz sand as a lost core. As the law of constant volume in metal forming is violated by compressible granular media, a simulation approach using a modified Drucker-Prager yield surface to model these materials is validated to provide a tool for efficient process design. Granular cores and magnesium alloy cores offer new possibilities in production of lightweight shafts by means of composite cold forging. Both process variants allow for higher weight savings than composite shafts based on aluminum cores.

scholarly journals Microstructure and Selected Properties of Cr3C2–NiCr Coatings Obtained by HVOF on Magnesium Alloy Substrates

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2775 ◽  
Author(s):  
Ewa Jonda ◽  
Leszek Łatka ◽  
Wojciech Pakieła
Keyword(s):  
Magnesium Alloy ◽  
Az31 Alloy ◽  
Composition Analysis ◽  
High Velocity Oxygen Fuel ◽  
Instrumented Indentation ◽  
Hvof Spraying ◽  
Alloy Substrate ◽  
Magnesium Az31 ◽  
Abrasive Erosion ◽  
Oxygen Fuel

In present work the Cr3C2–NiCr coating was deposited on magnesium alloy substrate with high velocity oxygen fuel (HVOF) spraying. The microstructure of the samples has been characterized by means of electron microscopy, SEM and phase composition analysis carried out. The porosity of coatings has been also estimated. Finally, tests of selected mechanical properties, such as instrumented indentation, abrasive erosion have been performed. The results of the investigations confirmed that dense, homogeneous and well-adhered Cr3C2–NiCr cermet coating is possible to obtain onto the magnesium AZ31 alloy substrate. Moreover, the coatings exhibit high resistance to erosion.

The Anticorrosive Properties of Sol-Gel Coating on AZ31 Magnesium Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 899-904 ◽  
Author(s):  
Yao Bo Hu ◽  
Fu Sheng Pan ◽  
Jing Feng Wang ◽  
Jian Peng
Keyword(s):  
Magnesium Alloy ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Strong Acid ◽  
Az31 Alloy ◽  
Dip Coating ◽  
Surface Finishes ◽  
Magnesium Az31 ◽  
Acid Environment ◽  
Dip Coating Technique

Titanium dioxide (TiO2) and silicon dioxide (SiO2) coating deposition were respectively performed by the dip coating technique on magnesium AZ31 alloy with extrusion surface finishes. The anticorrosive effect of different sol-gel coating was compared by measuring the weight loss when the samples were immerged in atmosphere, acetic acid aqueous solution with pH 5.0, distilled water with pH 6.4, aqueous 5% sodium chloride solution with pH 7.0. Morphological and structural characteristics of the coatings were analyzed by scanning electron microscopy (SEM), and semi quantitative analyses of the composition were performed by energy dispersive X-ray analysis (EDX) line scans. The results show that the anticorrosion properties of magnesium alloy with SiO2 or TiO2 are magnificently impactful in atmosphere. The anticorrosion effect of TiO2 coating is much preferable in a relatively strong acid environment.

Micro-Tensile Behavior at a High Temperature in an AZ31 Magnesium Alloy Processed by ECAP

2014 ◽  
Vol 783-786 ◽  
pp. 2726-2731 ◽  
Author(s):  
Jie Xu ◽  
Bin Guo ◽  
De Bin Shan ◽  
Terence G. Langdon
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Tensile Tests ◽  
Az31 Alloy ◽  
Tensile Behavior ◽  
Micro Forming ◽  
Ecap Processing ◽  
Forming Technology ◽  
Magnesium Az31

A magnesium AZ31 alloy was processed by ECAP at a temperature of 473 K using a die with a channel of 110o. The results show that the grain size was reduced from 5.4 μm to ~1.0 μm. Micro-tensile tests of the AZ31 alloy were conducted using as-received and ECAP-processed AZ31 alloy at a temperature of 473 K. The ductility of the AZ31 alloy can be improved significantly after ECAP processing at high temperature, which demonstrates a potential application in micro-forming technology for the UFG AZ31 alloy.

scholarly journals Strain Hardening in an AZ31 Alloy Submitted to Rotary Swaging

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 157
Author(s):  
Zuzanka Trojanová ◽  
Zdeněk Drozd ◽  
Kristýna Halmešová ◽  
Ján Džugan ◽  
Tomáš Škraban ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Work Hardening ◽  
Room Temperature ◽  
Az31 Alloy ◽  
First Order ◽  
Softening Mechanism ◽  
Rotary Swaging ◽  
Magnesium Az31 ◽  
Tension And Compression

An extruded magnesium AZ31 magnesium alloy was processed by rotary swaging (RSW) and then deformed by tension and compression at room temperature. The work-hardening behaviour of 1–5 times swaged samples was analysed using Kocks-Mecking plots. Accumulation of dislocations on dislocation obstacles and twin boundaries is the deciding factor for the strain hardening. Profuse twinning in compression seems to be the reason for the higher hardening observed during compression. The main softening mechanism is apparently the cross-slip between the pyramidal planes of the second and first order. A massive twinning observed at the deformation beginning influences the Hall-Petch parameters.

scholarly journals Silane coatings modified with hydroxyapatite nanoparticles to enhance the biocompatibility and corrosion resistance of a magnesium alloy

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26127-26144
Author(s):  
Aida Nikbakht ◽  
Changiz Dehghanian ◽  
Rasoul Parichehr
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Cell Viability ◽  
Hydroxyapatite Nanoparticles ◽  
Magnesium Az31

Incorporation of hydroxyapatite nanoparticles in silane coatings improves both corrosion resistance and cell viability on magnesium AZ31 implants.

Characterization of mechanical property of magnesium AZ31 alloy sheets for warm temperature forming

2015 ◽  
Vol 93 ◽  
pp. 204-217 ◽  
Author(s):  
Youngwoo Koh ◽  
Daeyong Kim ◽  
Dong-Yoon Seok ◽  
Jeonghwan Bak ◽  
Sang-Woo Kim ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Az31 Alloy ◽  
Warm Temperature ◽  
Magnesium Az31

ACCUMULATIVE ROLL BONDING OF AZ31 MAGNESIUM ALLOY

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2833-2939 ◽  
Author(s):  
S. M. FATEMI-VARZANEH ◽  
A. ZAREI-HANZAKI ◽  
M. HAGHSHENAS
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Accumulative Roll Bonding ◽  
Az31 Alloy ◽  
Thickness Reduction ◽  
Az31 Magnesium Alloy ◽  
Total Strain ◽  
Roll Bonding ◽  
Fine Grain

This work conducted to investigate the effects of accumulative roll bonding (ARB) method on achieving the ultra-fine grain microstructure in AZ31 alloy. Accordingly, a number of ARB routes at 400°C, applying thickness reductions per pass of 35%, 55%, and 85% were performed. The results indicate that both the final grain size and the degree of bonding have been dictated by the thickness reduction per pass. The larger pass reductions promote a higher degree of bonding. Increasing the total strain stimulates the formation of a more homogeneous ultra fine grain microstructure.

Magnesium Alloy AZ31 - Short Carbon Fiber Composite Obtained by Pressure Die Casting

2015 ◽  
Vol 229 ◽  
pp. 115-122 ◽  
Author(s):  
Anita Olszówka-Myalska ◽  
Jerzy Myalski
Keyword(s):  
Magnesium Alloy ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Die Casting ◽  
Az31 Alloy ◽  
Chamber Pressure ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31 ◽  
Pressure Die Casting ◽  
Short Carbon

The application of short carbon fibers in magnesium alloy AZ31 matrix composite fabrication by cold chamber pressure die casting was presented. A technological procedure of small-sized and complex-shaped composite casts manufacturing was shown. The microstructure of the composite was characterized as well as its mechanical properties, friction coefficient and wear resistance. The application of mechanical stirring of melted AZ31 alloy with short fibers and then AZ31-Cf suspension pressure die casting ensured obtaining casts with the reinforcing phase correctly distributed and well bonded with the matrix. Comparision of the AZ31-Cf composite with the AZ31 alloy properties, cast in the same conditions, revealed a considerable increase in bending strength and hardness, and some improvement of ductility and sliding friction parameters as a result of short carbon fibers application.

Sign in / Sign up

Export Citation Format

Share Document