Automated Semi-Solid Forging of Steel Components by Means of Thixojoining

At the Institute of Metal Forming (IBF) current investigations within the framework of the Collaborative Research Centre 289 are mainly concentrated on forming of semi-solid precursor material of the steel grades X210CrW12 and 100Cr6. One important task is the precise temperature for the composition of solid and liquid phase fraction in the preheated billet. Experimental measurements and numerical simulations show significant heat losses during transport of the billet and after its insertion into the die. These developing temperature gradients influence strongly the resulting temperature field in the formed component. In case of the forming tools the critical increase of the temperature depending on the tool material is shown. As fundamental research in the field of thixojoining the temperature development of the inserts is analysed and demonstrates the feasibility of joining higher and lower melting materials into the semi-solid matrix.

Download Full-text

Steel Grades Adapted to the Thixoforging Process: Metallurgical Structures and Mechanical Properties

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.712 ◽

2006 ◽

Vol 116-117 ◽

pp. 712-716 ◽

Cited By ~ 13

Author(s):

Marc Robelet ◽

Ahmed Rassili ◽

Dirk Fischer

Keyword(s):

Mechanical Properties ◽

Liquid Fraction ◽

Solidus Temperature ◽

Process Temperature ◽

Heating Process ◽

Work Piece ◽

Inductive Heating ◽

Steel Grades ◽

Automotive Part ◽

Semi Solid

Thixoforming of steel offers the advantages of casting technology in combination with high mechanical strength that can only be achieved by forging. The progress in establishing this technology in industry depends on the success in the development of suitable steel grades. Recent investigations dealt with the development of steel grades that are especially adapted to the thixoforming process. For this, alloys were developed with a lower solidus temperature and a wider process temperature range compared to classic forging steels. In consequence, the inductive heating process is more tolerant to inaccuracies and for a given liquid fraction the process temperature window is easier to handle. It is desired to obtain great degrees of deformation at rather low forming forces as these parameters determine the size of the needed presses. This behaviour is affected by the present liquid fraction in the slug and the heat transfer between work piece and die. It was detected that variations of the forming force have a direct influence on the quality of the thixoformed parts. In order to make the thixoforming technology of steels competitive versus other forming technologies, the parts must show a favourable microstructure and thus, good in-use properties. In this paper various solutions are compared. The main results obtained in the optimization research, namely, the steel grades adapted to semi-solid forming, the resulting process parameters and the mechanical properties of thixoforming parts will be presented for two exemplary steel grades. By producing a real automotive part, thixoforging of steels with regard to the adapted materials and to the ongoing industrial implementation of this process is proved.

Download Full-text

Multi-pass friction stirred clad welding of dissimilar joined AA6061 aluminium alloy and brass

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.12.4.2018.22.0368 ◽

2018 ◽

Vol 12 (4) ◽

pp. 4285-4299

Author(s):

Nora Osman ◽

Zainuddin Sajuri ◽

Mohd Zaidi Omar

Keyword(s):

Mechanical Properties ◽

Tool Steel ◽

Microstructural Analysis ◽

Welding Process ◽

Fusion Welding ◽

Tool Steels ◽

Aa6061 Aluminium Alloy ◽

Aisi D2 ◽

Semi Solid ◽

Aisi D2 Tool Steel

Tool steels are commonly used to cut metal materials due to their distinctive hardness, resistance to abrasion and deformation. However, tool steels are difficult to be joined using conventional fusion welding process. In this study, a thixotropic property of metal was utilised to butt-join an AISI D2 tool steel by using uncommon direct partial re-melting (DPRM) method. A high frequency of induction heating is used to apply the DPRM method. From the recent study, there are many methods in achieving the globular microstructure with the success of semi-solid joining process. Though, very less information on the microstructural effect of semi-solid joining on the mechanical properties was reported. This study aims to analyse the effect of uniaxial force on the microstructural evolution and mechanical properties of the thixo-joint of D2 tool steel. The microstructural analysis showed the diffusion occurred between the grains of the thixo-joint sample with 2.5 N uniaxial force. The maximum strength of the thixo-joint sample with force was 652 MPa. This was slightly higher than the as-received sample and the thixo-joint sample without force. The average hardness value of the thixo-joint sample was 400 HV due to the transformation of ferrite to the metastable austenite.

Download Full-text

Research on Semi-Solid Deformation and Forging Behavior of Ti14 Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.1373 ◽

2007 ◽

Vol 546-549 ◽

pp. 1373-1378 ◽

Cited By ~ 1

Author(s):

Yong Qing Zhao ◽

J.F. Wei ◽

Wei Lu Wu ◽

P. Guo

Keyword(s):

Mechanical Properties ◽

Grain Boundaries ◽

Room Temperature ◽

Low Cost ◽

Coarse Grain ◽

Solid Deformation ◽

Comprehensive Properties ◽

Fine Microstructure ◽

Semi Solid ◽

Solid Forging

Titanium and its alloys are widely used in industries due to their excellent comprehensive properties. However, their high-cost limits their applications in civil, therefore the research on low cost titanium technology is necessary. In the present study, the semi-solid deformation behavior of Ti14 burn resistant alloy was investigated. The results indicated that Ti2Cu melting phases within grains and at grain boundaries grow to form coarse grain boundaries and network structures during Ti14 alloy semi-solid deformation. Its microstructure was coarse and the grain boundary was wide after semi-solid forging, leading to low plasticity at room temperature. Recrystallizing heat treatment leads to fine microstructure, which is similar to that of conventional forging, resulting in improvement of tensile mechanical properties. The mechanical properties of semi-solid forging are similar to that of conventional one at high temperature.

Download Full-text

Semi-Solid Forging of Mg Alloy AZX1311 and Mechanical Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.846.72 ◽

2020 ◽

Vol 846 ◽

pp. 72-76

Author(s):

Shinichi Nishida ◽

Makoto Hagiwara ◽

Kentaro Tsunoda ◽

Ryoma Nakanishi ◽

Tatsuya Tanaka ◽

...

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Dimensional Accuracy ◽

Solid Material ◽

Forging Process ◽

Forming Load ◽

Automotive Parts ◽

Manufacturing Methods ◽

Semi Solid ◽

Solid Forging

This paper describes basic property in semi-solid forging method of magnesium alloy AZX1311. In the semi-solid forging process, an arbitrary fraction of solid is selected at a temperature between the liquidus and the solidus line and rapidly cooled and coagulated simultaneously with deformation of the material in a die to obtain a product. In addition, the magnesium alloy AZX1311 has excellent castability and mechanical properties. In recent years, the use of magnesium alloys for home electric appliances and automotive parts has been increasing because weight reduction can be achieved. These main manufacturing methods are casting and forging. However, these manufacturing methods have disadvantages such as large forming load and poor dimensional accuracy. Therefore, the semi-solidification forging method can improve these disadvantages. In this study, a forged semi-solid material and air cooled semi-solid material were produced using a servo press machine. Focused on impurities, porosity and microstructure. A forged semi-solid material could be produced. A semi-solid structure could be observed.

Download Full-text

Development of Aluminum-Lithium Alloys Processed by the Rheo Container Process

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.513 ◽

2006 ◽

Vol 116-117 ◽

pp. 513-517 ◽

Cited By ~ 1

Author(s):

Roger Sauermann ◽

Bernd Friedrich ◽

T. Grimmig ◽

M. Buenck ◽

Andreas Bührig-Polaczek

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Tensile Strength ◽

Collaborative Research ◽

Induction Melting ◽

High Quality ◽

Aluminum Lithium ◽

Semi Solid ◽

Aluminum Lithium Alloys ◽

Lithium Alloys

This investigation describes the development and evaluation of thixoformable alloys on Al-Li-Mg basis in the scope of the collaborative research center SFB 289 at RWTH Aachen University. Scandium and zirconium was added to Al-Li2.1-Mg5.5 (A1420) with the aid of DoE (Design of Experiments) and precursor billets were manufactured by pressure induction melting (PIM). To evaluate the thixoformability of the synthesized alloys high-quality semi solid processed demonstrators were manufactured by the Rheo-Container-Process. Subsequent heat treatment raised the mechanical properties to maximum values of tensile strength of 432MPa, yield strength of 220MPa and an elongation of 13%. The RCP-Process was designed for the special requirements of this high reactive alloy. The paper will present extraordinary benefits in terms of properties and process simpleness for the semi-solid processing of Al-Li alloys.

Download Full-text

Effect of uniaxial load on microstructure and mechanical properties of Thixo-joint AISI D2 tool steel

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.13.2.2019.17.0414 ◽

2019 ◽

Vol 13 (2) ◽

pp. 5006-5020 ◽

Cited By ~ 1

Author(s):

F. Adnan ◽

Z. Sajuri ◽

M. Z. Omar

Keyword(s):

Mechanical Properties ◽

Tool Steel ◽

Microstructural Analysis ◽

Welding Process ◽

Fusion Welding ◽

Tool Steels ◽

Aisi D2 ◽

Semi Solid ◽

Aisi D2 Tool Steel ◽

Microstructural Effect

Tool steels are commonly used to cut metal materials due to their distinctive hardness, resistance to abrasion and deformation. However, tool steels are difficult to be joined using conventional fusion welding process. In this study, a thixotropic property of metal was utilised to butt-join an AISI D2 tool steel by using uncommon direct partial re-melting (DPRM) method. A high frequency of induction heating is used to apply the DPRM method. From the recent study, there are many methods in achieving the globular microstructure with the success of semi-solid joining process. Though, very less information on the microstructural effect of semi-solid joining on the mechanical properties was reported. This study aims to analyse the effect of uniaxial force on the microstructural evolution and mechanical properties of the thixo-joint of D2 tool steel. The microstructural analysis showed the diffusion occurred between the grains of the thixo-joint sample with 2.5 N uniaxial force. The maximum strength of the thixo-joint sample with force was 652 MPa. This was slightly higher than the as-received sample and the thixo-joint sample without force. The average hardness value of the thixo-joint sample was 400 HV due to the transformation of ferrite to the metastable austenite.

Download Full-text

Research on the Microstructure and Mechanical Property of Ti-7Cu Alloy after Semi-Solid Forging

High Temperature Materials and Processes ◽

10.1515/htmp-2015-0014 ◽

2016 ◽

Vol 35 (6) ◽

pp. 543-550 ◽

Cited By ~ 3

Author(s):

Yongnan Chen ◽

Yazhou Huo ◽

Yongqing Zhao ◽

Zhiping Sun ◽

Fan Bai

Keyword(s):

Mechanical Properties ◽

Mechanical Property ◽

Grain Size ◽

Solid State ◽

Grain Boundary ◽

Dynamic Recrystallization ◽

Precipitation Behavior ◽

Semi Solid ◽

Solid Forging ◽

Microstructure And Mechanical Property

AbstractThe present work is focused on the development of microstructure of Ti-7Cu alloy as a function of forging temperature and forging ratio in semi-solid state and the influence of resulting microstructure on the mechanical properties. The experimental results showed that the dynamic recrystallization occurred during semi-solid forging and the grain refinement was attained which is considered to be favorable for improving the semi-solid formability. The grain size increased with forging temperature and decreased with forging ratio. Forging temperature has a significant effect on the precipitation behavior in grain boundary regions during the semi-solid processing. More acicular-Ti2Cu tended to precipitate in grain boundary regions with higher forging temperature and finally formed precipitates zones adjacent to grain boundaries after forged at 1,100°C. High ultimate tensile strengths and low elongation have been achieved after semi-solid forging. The strength and hardness decreased with increase of forging temperature, while the ductility increased with increase of forging ratio. The relative contributions of tensile properties were attributed to the varieties of grain size and the distribution of Ti2Cu precipitates obtained by semi-solid forging.

Download Full-text