scholarly journals An Innovative Approach of Parameter Loading Path Design for Grain Refinement and Its Application in Ni80A Superalloy

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6703
Author(s):  
Guo-Zheng Quan ◽  
Yan-Ze Yu ◽  
Xue Sheng ◽  
Kun Yang ◽  
Wei Xiong
Keyword(s):  
Strain Rate ◽  
Grain Refinement ◽  
Deformation Mechanism ◽  
Processing Parameters ◽  
Loading Path ◽  
Processing Parameter ◽  
Compression Process ◽  
Innovative Method ◽  
Path Design ◽  
Loading Path Design

In order to obtain the desired mechanical properties of products, an innovative method of loading parameter designs for acquiring the desired grain refinement is proposed, and it has been applied in the compression process of Ni80A superalloy. The deformation mechanism maps derived from processing maps based on the Dynamic Materials Model (DMM) theory were constructed, since the critical indicator values corresponding to dynamic recrystallization (DRX) and dynamic recovery (DRV) mechanisms were determined. The processing-parameter domains with DRX mechanisms were separated from the deformation mechanism map, while such domains were chaotic and difficult to apply in innovative parameter loading path design. The speed-loading path derived from strain rate-loading path in a compression process was pursued. The grain refinement domains are discretized into a finite series of sub-domains with clear processing parameters, and the optimal strain rate of each sub-domain is determined by step-by-step finite element simulation. A 3D response surface of the innovative optimal loading path of strain rate was fitted by interpolating methods. Finally, the isothermal compression experiments for Ni80A superalloy were conducted, and the microstructure observations indicated that the desired grain refinement was achieved. This innovative method of parameter loading path design contributes to the microstructure adjustment of the alloys with DRX mechanism.

scholarly journals Investigation of Punch Shape and Loading Path Design in Hydro-Flanging Processes of Aluminum Alloy Tubes

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 636
Author(s):  
Yeong-Maw Hwang ◽  
Hong-Nhan Pham ◽  
Hiu-Shan Rachel Tsui
Keyword(s):  
Aluminum Alloy ◽  
Thickness Distribution ◽  
Loading Path ◽  
Hydraulic Power ◽  
Hole Radius ◽  
Path Design ◽  
Hole Flanging ◽  
Loading Path Design ◽  
Punch Shape ◽  
Deform 3D

Hydro-joining is composed of hydro-piercing, hole flanging and nut-inlaying processes. In this study, a new hydro-flanging process combining hydro-piercing and hydro-flanging is proposed. An internal pressured fluid is used as the supporting medium instead of a rigid die. Three kinds of punch head shapes are designed to explore the thickness distribution of the flanged tube and the fluid leakage effects between the punch head and the flanged tube in the hydro-flanging process. A finite element code DEFORM 3D is used to simulate the tube material deformation behavior and to investigate the formability of the hydro-flanging processes of aluminum alloy tubes. The effects of various forming parameters, such as punch shapes, internal pressure, die hole diameter, etc., on the hydro-flanged tube thickness distributions are discussed. Hydro-flanging experiments are also carried out. The die hole radius is designed to make the maximum internal forming pressure needed smaller than 70 MPa, so that a general hydraulic power unit can be used to implement the proposed hole flanging experiments. The flanged thickness distributions are compared with simulation results to verify the validity of the proposed models and the designed punch head shapes.

scholarly journals Warpage Optimisation Using Recycled Polycar-bonates (PC) on Front Panel Housing

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1416
Author(s):  
Nur Aisyah Miza Ahmad Tamizi ◽  
Shayfull Zamree Abd Rahim ◽  
Abdellah El-hadj Abdellah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Marcin Nabiałek ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Processing Parameters ◽  
Front Panel ◽  
Processing Parameter ◽  
Mechanical Recycling ◽  
Great Opportunity ◽  
Average Value ◽  
Optimal Processing ◽  
Materials Used ◽  
Optimisation Methods

Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.

scholarly journals Optimisation of Shrinkage and Strength on Thick Plate Part Using Recycled LDPE Materials

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1795
Author(s):  
Norshahira Roslan ◽  
Shayfull Zamree Abd Rahim ◽  
Abdellah El-hadj Abdellah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Katarzyna Błoch ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Thick Plate ◽  
Processing Parameters ◽  
Processing Parameter ◽  
Plastic Injection Moulding ◽  
Optimal Setting ◽  
Quality Of Products ◽  
Validation Tests ◽  
Plastic Injection

Achieving good quality of products from plastic injection moulding processes is very challenging, since the process comprises many affecting parameters. Common defects such as warpage are hard to avoid, and the defective parts will eventually go to waste, leading to unnecessary costs to the manufacturer. The use of recycled material from postindustrial waste has been studied by a few researchers. However, the application of an optimisation method by which to optimise processing parameters to mould parts using recycled materials remains lacking. In this study, Response Surface Methodology (RSM) and Particle Swarm Optimisation (PSO) methods were conducted on thick plate parts moulded using virgin and recycled low-density polyethylene (LDPE) materials (100:0, 70:30, 60:40 and 50:50; virgin to recycle material ratios) to find the optimal input parameters for each of the material ratios. Shrinkage in the x and y directions increased in correlation with the recycled ratio, compared to virgin material. Meanwhile, the tensile strength of the thick plate part continued to decrease when the recycled ratio increased. R30 (70:30) had the optimum shrinkage in the x direction with respect to R0 (100:0) material where the shrinkage increased by 24.49% (RSM) and 33.20% (PSO). On the other hand, the shrinkage in the y direction for R30 material increased by 4.48% (RSM) and decreased by 2.67% (PSO), while the tensile strength of R30 (70:30) material decreased by 0.51% (RSM) and 2.68% (PSO) as compared to R0 (100:0) material. Validation tests indicated that the optimal setting of processing parameter suggested by PSO and RSM for R0 (100:0), R30 (70:30), R40 (60:40) and R50 (50:50) was less than 10%.

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