TY - BOOK

T1 - Forming behavior of Ca containing Mg alloys

AU - Papenberg, Nikolaus Peter

N1 - no embargo

PY - 2023

Y1 - 2023

N2 - This work is intended to expand the understanding of lean Mg alloys forming behavior, which are precipitation hardenable due to alloying with calcium. Special attention is given to the investigation of the die forging process. Lean Mg alloys are defined by a low overall amount of alloying elements, which are intended to be used in the most efficient way. The limited basic strength of these alloys is intended to support the forming process, while the strengths required for use can be achieved by precipitation hardening in a subsequent heat treatment. Most scientific investigations of Mg forming processes deal with extrusion or rolling, as these processes represent most of the untapped market potential. However, forging processes, with their inherent high flexibility in terms of process conditions and feedstock material, offer a good entry point for industry into the complex subject of Mg manufacturing processes. Also, the production of finished forged Mg components presents advantages in analysis and demonstrability compared to extruded or rolled products, since the latter are mainly semi-finished products. In the present work, a precipitation hardenable Mg-Al-Ca-Mn-Zn alloy (AXMZ1000) with a low total alloy content (< 2 weight percent) was investigated with respect to its suitability for forging processes. The forming behavior from laboratory to industrial scale forming was analyzed. The process parameters, the forging stock and the heat treatments were varied in order to evaluate changes in the process and microstructural behavior as well as the mechanical properties of the produced parts. The forming behavior of cast feedstock was described using a processing map and verified by forging trials on laboratory and industrial scale. In-depth investigations on mechanical properties, using tensile and fatigue testing, as well as microstructural development was done on isothermal forged parts. Based on the analyses performed, it was possible to show a dependence of the forged components on the stock material used. Extruded material significantly improved the mechanical properties of the forged components. The differences between forming tests in laboratory and industrial scale were investigated in detail and differences, problem areas as well as limitations were pointed out.

AB - This work is intended to expand the understanding of lean Mg alloys forming behavior, which are precipitation hardenable due to alloying with calcium. Special attention is given to the investigation of the die forging process. Lean Mg alloys are defined by a low overall amount of alloying elements, which are intended to be used in the most efficient way. The limited basic strength of these alloys is intended to support the forming process, while the strengths required for use can be achieved by precipitation hardening in a subsequent heat treatment. Most scientific investigations of Mg forming processes deal with extrusion or rolling, as these processes represent most of the untapped market potential. However, forging processes, with their inherent high flexibility in terms of process conditions and feedstock material, offer a good entry point for industry into the complex subject of Mg manufacturing processes. Also, the production of finished forged Mg components presents advantages in analysis and demonstrability compared to extruded or rolled products, since the latter are mainly semi-finished products. In the present work, a precipitation hardenable Mg-Al-Ca-Mn-Zn alloy (AXMZ1000) with a low total alloy content (< 2 weight percent) was investigated with respect to its suitability for forging processes. The forming behavior from laboratory to industrial scale forming was analyzed. The process parameters, the forging stock and the heat treatments were varied in order to evaluate changes in the process and microstructural behavior as well as the mechanical properties of the produced parts. The forming behavior of cast feedstock was described using a processing map and verified by forging trials on laboratory and industrial scale. In-depth investigations on mechanical properties, using tensile and fatigue testing, as well as microstructural development was done on isothermal forged parts. Based on the analyses performed, it was possible to show a dependence of the forged components on the stock material used. Extruded material significantly improved the mechanical properties of the forged components. The differences between forming tests in laboratory and industrial scale were investigated in detail and differences, problem areas as well as limitations were pointed out.

KW - Magnesium wrought alloy

KW - Magnesium lean alloy

KW - Mg¿Al¿Ca¿Mn¿Zn alloy

KW - Closed die forging

KW - Material characterization

KW - Artificial aging

KW - Magnesium Umformlegierung

KW - Magere Magnesium Legierung

KW - Mg¿Al¿Ca¿Mn¿Zn Legierung

KW - Gesenkschmieden

KW - Materialanalyse

KW - Warmaushärtung

U2 - 10.34901/mul.pub.2023.185

DO - 10.34901/mul.pub.2023.185

M3 - Doctoral Thesis

ER -