scholarly journals DETERMINING THE RHEOLOGICAL CHARACTERISTICS AND MODELING THE EXTRUSION PROCESS OF POWDER AND POROUS MATERIALS. PART 3: THE HOT EXTRUSION PROCESS

2017 ◽  
Vol 254 (4) ◽  
pp. 182-190
Author(s):  
V.N. Tsemenko ◽  
D.V. Fuk ◽  
S.V. Ganin
Author(s):  
A. Damodar Reddy ◽  
P.N. Karthikeyan ◽  
S. Krishnaraj ◽  
Adarsh Ajayan ◽  
K. Sunil Kumar Reddy ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 663
Author(s):  
Thomas Borgert ◽  
Werner Homberg

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.


2015 ◽  
Vol 817 ◽  
pp. 531-537 ◽  
Author(s):  
Tao Tang ◽  
Yi Chuan Shao ◽  
Da Yong Li ◽  
Ying Hong Peng

In order to study the influence of extrusion process on texture development of alloys, numerical simulation methods were used to simulate the round and shape extrusion process and deformation texture. Extrusion of Mg-Y magnesium alloy was carried out at the temperature of 673K with different ram speeds to verify the simulation results. Instead of using the Lagrangian FE method, the Arbitrary Lagrangian-Eulerian (ALE) method was employed in this study so that a more accurate description of the steady-state extrusion process can be achieved. By obtaining strain histories of specified material tracer particles, the coupling of deformation and crystal plasticity theory was applied to simulate the texture evolution in hot extrusion. The results showed that the texture simulation corresponded well with the experimental ones. The study proposes a method to analyze the steady-state extrusion process and texture evolution, and can be used as a useful tool in optimizing the extrusion process.


1993 ◽  
Vol 11 (1-4) ◽  
pp. 167-169
Author(s):  
Shigemitsu Kihara ◽  
Seiichi Matsumoto ◽  
Kazuo Saito ◽  
Hiroyuki Ogawa

Author(s):  
J. Joel ◽  
M. Anthony Xavior

Metal Matrix Composites (MMCs) based on Aluminum Alloys 2024, 6061 and 7075 reinforced with Graphene was fabricated using powder metallurgy process followed by hot extrusion process. The extruded samples were used for conducting the turning experiments to evaluate the machinability of the developed composites. Turning experiments were conducted in ACE Micromatic made CNC lathe as per the Design of Experiments (DOE) designed using L18 Taguchi’s mixed orthogonal array. Uncoated and DLC coated carbide inserts, along with three levels of cutting speeds, feed rates and depths of cut were considered for the turning experiments. During the experiments the cutting force generated was recorded “online” and subsequent to the experimentation the surface roughness generated on the work piece and the surface hardness for every trial were recorded. The influence of the cutting tool material and other cutting parameters on the machinability of composites was analyzed using ANOVA. The microstructural observation on the surface of the machined specimen reveals the detachment of reinforcement materials from the composite and their impact of the surface quality.


2011 ◽  
Vol 491 ◽  
pp. 233-240 ◽  
Author(s):  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Luca Tomesani

Tools are exposed to severe working conditions during the hot extrusion process. In particular, dies and mandrels can be subjected to an excessive amount of deformation as a result of the developed high cyclic loads and temperatures. In this scenario, a physical experiment reproducing the thermo-mechanical conditions of a mandrel in a porthole die was performed with the Gleeble machine on the AISI H11 tool steel with the aim to investigate the mechanisms that influence the die deformation. The design of experiment consisted of 4 levels of temperature, 3 levels of stress and 3 types of load, i.e. pure creep, pure fatigue and creep-fatigue. In all the testing conditions, a comparable pattern of the mandrel displacement-time curve was found reproducing the 3 stages of softening typical of the strain evolution in a standard creep test but with a marked primary phase. Thus, with the aim to identify an easy-applicable equation to estimate the die deformation, the time hardening creep law was chosen. Coefficients of the time-hardening law were optimized, for each testing condition, on the basis of experimental data starting from values for similar alloys taken from the literature. Results in terms of mandrel displacement were then compared to experimental data for the creep-fatigue condition at different stress and temperature levels. The values found were validated against additional experimental data performed with different specimen geometries. A good average agreement was found between experimental and numerical results. The developed procedure was then applied to an industrial die.


Author(s):  
P. Ashwath ◽  
M. Anthony Xavior ◽  
R. Rajendran

Abstract Looking at the background of the recent research on the area of the brake friction materials, composites are gaining the trust in being a potential replacement among the automobile sectors. The fabrication of the AA 2024 composites reinforced with 3 wt % Al2O3 is done using powder metallurgy technique followed by hot extrusion process. Current research work focuses on friction stir processed surface modified composites evaluated for the replacement of the currently used brake pads materials in automobile sectors. Surface characterization is carried out on the worn-out tracks of both brake materials developed and the counterpart employed using scanning electron microscope and XRD. The counterpart used in pin on disc configuration is exactly the material used in the automobile application (i.e. automobile brake disc plate material). Impact characteristics and tensile studies after friction stir processing (FSP) is studied as well. Coefficient of friction and wear loss characteristics in aspect of the tribological life of the composites developed is compared with the existing automobile brake pad components and found that FSP on composites served the purpose of the materials used in existing brake pads material.


2020 ◽  
Vol 275 ◽  
pp. 116348 ◽  
Author(s):  
Xiaoxue Chen ◽  
Guoqun Zhao ◽  
Guoliang Liu ◽  
Lu Sun ◽  
Liang Chen ◽  
...  

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