scholarly journals Powder Forging of in Axial and Radial Direction Graded Components of TRIP-Matrix-Composite

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 378
Author(s):  
Markus Kirschner ◽  
Sergey Guk ◽  
Rudolf Kawalla ◽  
Ulrich Prahl
Keyword(s):  
Powder Metallurgy ◽  
Radial Direction ◽  
Steel Matrix ◽  
Forming Process ◽  
Fully Integrated ◽  
Transformation Induced Plasticity ◽  
Graded Structure ◽  
Process Route ◽  
Material Systems ◽  
Graded Structures

Powder metallurgy is one way of producing complex, graded structures that could allow material systems to be produced with properties tailored to individual applications. However, powder metallurgy requires that the semi-finished products are very similar to the final component. It is much more economical to produce simple semi-finished products and then combine them by powder forging and simultaneous compaction than forming complex components with the desired graded structure. However, it is absolutely necessary that the graded structure of the semi-finished products is maintained during the forming process. In this study, pre-sintered cylindrical semi-finished products, consisting of axially graded as well as radially graded components, were produced by powder forging at 1100 °C. The microstructures, densities and mechanical properties of the final components were investigated to verify the effectiveness of the process route. It was observed that the components formed solid structures after compaction, in which the reinforcing ZrO2 particles were fully integrated into the transformation-induced plasticity steel matrix.

scholarly journals Forming Complex Graded and Homogeneous Components by Joining Simple Presintered Parts of TRIP-Matrix Composite through Powder Forging

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 543 ◽  
Author(s):  
Markus Kirschner ◽  
Stefan Martin ◽  
Sergey Guk ◽  
Ulrich Prahl ◽  
Rudolf Kawalla
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Steel Matrix ◽  
Forming Process ◽  
Form Complex ◽  
Transformation Induced Plasticity ◽  
Graded Structure ◽  
Material Systems ◽  
Significant Step ◽  
Graded Structures

The ability to fabricate complex graded structures would be a significant step towards the manufacturing of material systems with properties tailored to individual applications. While powder metallurgy has had some success in this regard, it requires that the semi-finished products be exactly similar to the final component. However, it is significantly cheaper to produce simple, semi-finished products and then join them to form complex components with the desired graded structure through powder forging and simultaneous compaction. It is also essential that the graded structure of the semi-finished products is retained during the forming process. In this study, pre-sintered cylindrical semi-finished products consisting of identical homogeneous layers as well as graded components consisting of non-identical homogeneous layers were joined using powder forging at 1100 °C. The microstructures and densities as well as the mechanical properties of the final components were investigated. It was observed that, upon compaction, the components formed solid structures, in which the reinforcing ZrO2 particles were completely integrated within the transformation-induced plasticity steel matrix. Finally, it was confirmed that the graded structure of the semi-finished products was retained in the final components.

Friction Characterisation for a Tumbling Self-Piercing Riveting Process

2021 ◽  
Vol 883 ◽  
pp. 27-34
Author(s):  
Simon Wituschek ◽  
Michael Lechner
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Vehicle Design ◽  
Numerical Investigations ◽  
Process Route ◽  
Friction Factors ◽  
Material Systems ◽  
Body Construction ◽  
Riveting Process ◽  
The Individual

Due to increasing demands regarding ecological and economic specifications in vehicle design, the effort required for production is continuously increasing. One trend is the increased use of multi-material systems, which are characterised by the use of different materials such as high-strength steels or aluminium alloys. In addition to the varying mechanical properties of the components, an increased number of variants accompanied by different geometries is leading to increasing challenges on body construction. For the assembly and connection of the individual components, conventional joining methods reach their limitations. Therefore, new joining methods are necessary, which feature properties of versatility and can adapt to process and disturbance variables. One way of achieving tailored joints is to use a tumbling self-piercing riveting process. For the design of the process route, numerical investigations are necessary for which a characterisation of the friction properties is necessary. This paper therefore investigates the contact and friction conditions that occur in a tumbling self-piercing riveting process. The individual contacts between the process components are identified and based on this, suitable processes for the characterisation of the friction factors - and coefficients are selected and performed.

Formation of Amorphous Graded Structure in Bi3Pb7 Intermetallic Compounds under Strong Gravitational Field

2009 ◽  
Vol 289-292 ◽  
pp. 357-360 ◽  
Author(s):  
Tsutomu Mashimo ◽  
Yusuke Iguchi ◽  
Rabaya Bagum ◽  
Tomokazu Sano ◽  
S. Takeda ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Amorphous Structure ◽  
Strong Gravitational Field ◽  
Graded Structure ◽  
Homogeneous Phase ◽  
Graded Structures ◽  
Gravity Direction

A visible four-layers structure with anomalous nano-sturucture was formed from a homogeneous -phase Bi3Pb7 intermetallic compound under a strong gravitational field (1.02x106 G, 130°C, 100 hours). In the 4th layer (lowest-gravity region), pure Bi particles precipitate. In the 2nd 3rd layers, composition graded structures, where Pb content increased along the gravity direction, were formed. It was found that the very broad XRD peak appeared in the 2nd layer, which indicated that an amorphous structure was contained.

Local Graded Structure in 6.5wt%Si-Fe Alloy and the Effect on Ductility

2005 ◽  
Vol 492-493 ◽  
pp. 59-62 ◽  
Author(s):  
Qiang Shen ◽  
Ran Li ◽  
Lian Meng Zhang
Keyword(s):  
Phase Composition ◽  
Powder Metallurgy ◽  
Deformation Behavior ◽  
Powder Metallurgy Method ◽  
Silicon Phase ◽  
Silicon Iron ◽  
Graded Structure ◽  
Composition And Structure ◽  
High Silicon ◽  
Si Content

The changes of phase composition and structure evolvement of Fe and Si powders with the ratio of 6.5wt%Si to 93.5wt%Fe were mainly studied. It is found that, the local graded structure, Fe-Fe(Si)-Fe3Si-(FeSi)-Si, forms due to the obvious diffusion and the alloying reaction between Fe and Si powders when sintering at 900-975oC. The graded structure, in which the high silicon phase based on Fe-Si alloys is packed by the low silicon solution based on Fe, exhibits a graded concentration of Si distribution. And most of the Fe-containing phase remains a state of lower Si content, less than that of 3wt%Si-Fe alloy, thus provides the good deformation behavior of rolling and cutting for the compacts. Therefore, it is feasible for the high silicon iron sheets to be produced by the powder metallurgy method.

Comparative Study for Springback Prediction on Single Point Incremental Forming Process

2014 ◽  
Vol 622-623 ◽  
pp. 375-381
Author(s):  
Valentin Oleksik ◽  
Adrian Pascu ◽  
Ioan Bondrea ◽  
Eugen Avrigean ◽  
Liviu Rosca
Keyword(s):  
Comparative Study ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Machined Surface ◽  
Fully Integrated ◽  
Explicit Dynamic ◽  
Springback Prediction

The present paper proposes a comparative study in order to determine the springback in single point incremental forming process. Using the Ls-Dyna software the process was simulated for one piece in frustum of pyramid shape. In the end of the explicit dynamic analysis, it was run, using the same software, an implicit analysis to determine the springback. For this comparison study we selected four different shell formulations. The results obtained in this simulation were compared with those obtained experimentally for the same part. The experimental research was conducted on a robot and, on the opposite side of the machined surface, an Aramis measuring optical system was placed to allow the online determination of deformations, displacements and thinning of material. Also, using this system, the springback was determined at the end of forming process. The closest values were obtained when using fully integrated formulation with thickness-stretch with 11 integration points on material thickness.

Analysis on Formation Causes for Defects of Powder Metallurgy Flyweights

2010 ◽  
Vol 426-427 ◽  
pp. 599-602
Author(s):  
X.P. Shen ◽  
X.Y. Wang ◽  
D.M. Liu ◽  
M. Chen ◽  
C.T. You ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Complex Structure ◽  
Forming Process ◽  
Size Accuracy ◽  
Powder Forming ◽  
Compaction Method

The flyweight of powder metallurgy is a complex structure part of VE distribution pump. The components of the powder forming process often contain the defects such as instability of the quality, over tolerance of the size accuracy, and disqualification of the appearance. By analyzing the causes of defects and corresponding measures is taken. A once pressing compaction method is used to produce qualified products.

A Study on Al2O3/SiC/B4C Reinforced Cu-Sn Matrix Composite by Warm Compaction Powder Metallurgy

2015 ◽  
Vol 1128 ◽  
pp. 123-126
Author(s):  
Kerim Emre Öksüz
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Optical Microscope ◽  
Matrix Composites ◽  
Forming Process ◽  
Preparation Methods ◽  
Warm Compaction ◽  
Wear Tests ◽  
Structural Aspects ◽  
Properties Of Composites

Increasing density is the best way to increase the performance of powder metallurgy materials. Conventional powder metallurgy processing can produce copper green compacts with density less than 8.3g/cm3(a relative density of 93%). Warm compaction, which is a simple and economical forming process to prepare high density powder metallurgy parts or materials. CuSn matrix composites with %2 weight fractions of reinforcement particles were prepared using warm compaction and sintering. Micro-structural aspects were observed by optical microscope. Density, hardness and wear tests were also performed. Abrasion resistance measurements were used to study the abrasive behaviors of CuSn matrix and its composites. The effects of reinforcement and preparation methods on the microstructure and mechanical properties of composites have been investigated.

A Novel Forming Process for Powder Metallurgy of Superalloys

2014 ◽  
Vol 622-623 ◽  
pp. 833-839 ◽  
Author(s):  
Qian Bai ◽  
Jian Guo Lin ◽  
Gao Feng Tian ◽  
Daniel S. Balint ◽  
Jin Wen Zou
Keyword(s):  
Powder Metallurgy ◽  
Relative Density ◽  
High Performance ◽  
Low Cost ◽  
Hot Isostatic Pressing ◽  
Hot Extrusion ◽  
Forming Process ◽  
Isostatic Pressing ◽  
Wide Range ◽  
Forming Temperature

Powder metallurgy (PM) of nickel-based superalloys has been used for a wide range of products owing to their excellent special properties in processing and applications. Typical processes for high performance PM superalloys include hot isostatic pressing, hot extrusion and hot isothermal forging. Hot isostatic pressing is normally conducted at a high temperature, by using a low pressure for a long time in a closed vessel, resulting in high cost and low product efficiency. In this paper a novel forming process, i.e. direct powder forging for powder metallurgy of superalloys has been proposed. In this process, the encapsulated and vacuumed powder is heated up to the forming temperature and forged directly to the final shape, by using a high forming load for a very short time. Direct powder forging is a low-cost and energy-saving process compared to conventional PM processes, and in addition, press machines of conventional forging can be used for direct powder forming process. In direct powder forging it is important to control the relative density of the deformed part since the existence of voids could reduce the mechanical strength and fatigue life. In this paper, feasibility tests of direct powder forging are presented. Microstructure, relative density and hardness of the formed specimen were studied.

Preparation and Properties of Cu-10Sn Alloy Infiltrated 316L Stainless Steel Composites

2012 ◽  
Vol 503-504 ◽  
pp. 552-555 ◽  
Author(s):  
Xia Yang ◽  
Ying Long Bai ◽  
Meng Xu ◽  
Shi Ju Guo
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Matrix Composite ◽  
316L Stainless Steel ◽  
Corrosion Potential ◽  
Steel Matrix ◽  
Mechanical Properties And Corrosion ◽  
Steel Matrix Composite

A new method to produce powder metallurgy (P/M) 316L stainless steel matrix composite by pressureless infiltrating Cu-10Sn alloy was studied. The effect of various compaction pressures and infiltrating temperatures on the microstructure, mechanical properties and corrosion resistance was investigated. The results show that high density P/M 316L stainless steel matrix composite could be achieved by infiltration. A maximum relative density of 98% was achieved, provided that the porosity of the skeleton was controlled at 18%~22%. After infiltration, hardness of the samples increased from 49 HRB to 89 HRB. Moreover, the critical corrosion potential reached -212 mV, close to the level of as cast 316L stainless steel. The hardness of infiltrated composite of the same density decreased with increase in initial skeleton density. It was necessary to prevent the egregious grain growth while the infiltrating temperature was too high.

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