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.

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.

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.

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.

Use of Nanoindentation to Characterise the Plasma Damage Region in Low-k Dielectric Films

2006 ◽  
Author(s):  
Jon M. Molina-Aldareguia ◽  
Maria R. Elizalde ◽  
Ibon Ocan˜a ◽  
Javier Gil-Sevillano ◽  
Jose´ M. Marti´nez-Esnaola ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Depth Resolution ◽  
Dielectric Materials ◽  
Dynamical Response ◽  
Indentation Modulus ◽  
Depth Sensing ◽  
K Value ◽  
Graded Structure ◽  
Graded Structures ◽  
Low K

The thermo-mechanical robustness of interconnect structures is a key reliability concern for integrated circuits. The introduction of new low dielectric constant (low-k) materials with deteriorated mechanical strength (i.e., Young Modulus decreases exponentially with film porosity, which is needed to lower the k value of the dielectric materials) to meet the RC delay goals increase the risk of mechanical adhesive and/or cohesive failure of the device during packaging or even in service. Therefore, the mechanical properties of low-k dielectrics must be studied in detail. This is made very challenging by the fact that they have submicron thickness and that they often display a graded structure due to the damage introduced by exposure to different plasmas during processing. In this context, we demonstrate that nanoindentation is very well suited to study this type of materials. We will show how conventional depth sensing nanoindentation is of limited value to characterise the extent of the plasma induced damage because this extents just a few tens of nanometres and the graded structure can not be sampled with enough depth resolution. However, nanoindentation in modulus mapping mode can achieve enough depth resolution to characterise such nanoscale graded structures. In this technique, the electrostatic force acting on the indenter tip is sinusoidally modulated, while contact mode imaging at a very small force is performed. The dynamical response is then analyzed to extract the local indentation modulus of the sample at each pixel. By using this technique, we have depth profiled the mechanical properties of the plasma induced damage region of OSG films exposed to different plasmas, by acquiring modulus maps as a function of thickness removed in wear experiments. The results correlate well with the density depth profiles derived from X-Ray Reflectivity measurements.

The Graded Origami Structures

2015 ◽  
Author(s):  
Ruikang Xie ◽  
Jianmin Li ◽  
Yan Chen
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Engineering Application ◽  
Geometric Parameters ◽  
Sandwich Beams ◽  
Three Point Bending ◽  
Graded Structure ◽  
Sector Angle ◽  
Graded Structures ◽  
Bending Response

There are many excellent graded structures existing in nature to optimize the mechanical properties in various load situations by adjusting the distribution of materials. In this research, rigid origami and graded structure concept are combined together to form the graded origami structures. Seven methods are proposed, including changing the length of crease lines, changing the sector angle, changing the number of units, and the combinations of them. Two rigid origami patterns, Miura-ori and Arc-Miura, are chosen to generate the graded origami structures, and the geometric parameters of each pattern are studied. For engineering application, quasi-static three-point bending response of sandwich beams with graded Miura-ori core based on changing the number of units and changing both the length of crease lines and the sector angle is explored. The investigation reveals that sandwich beams with graded Miura-ori core have preferable energy absorption capability in this load situation compared with the normal Miura-ori core.

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