Due to their design, hollow cavity and filled sodium, hollow head and sodium filled engine valves (HHSVs) have superior performance to traditional solid valves in terms of mass and temperature reduction. This paper presents a new manufacturing method for 42Cr9Si2 steel hollow head and sodium filled valves. An inertia friction welding process parameter optimization was conducted to obtain a suitable process parameter range. The fatigue strength of 42Cr9Si2 steel at elevated temperatures was evaluated by rotating bending fatigue test with material specimens. Performance evaluation tests for real valve components were then carried out using a bespoke bench-top apparatus, as well as a stress evaluation utilizing a finite element method. It was proved that the optimized friction welding parameters of HHSV can achieve good welding quality and performance, and the HHSV specimen successfully survived defined durability tests proving the viability of this new method. The wear resistance of the HHSV specimens was evaluated and the corresponding wear mechanisms were found to be those classically defined in automotive valve wear.
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http://dx.doi.org/10.3390/ma12071123 | DOI Listing |
Materials (Basel)
December 2024
School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
TC17 titanium alloy is widely used in the aviation industry for dual-performance blades, and linear friction welding (LFW) is a key technology for its manufacturing and repair. However, accurate evaluation of the mechanical properties of TC17-LFW joints and research on their joint fracture behavior are still not clear. Therefore, this paper used the finite element numerical simulation method (FEM) to investigate the mechanical behavior of the TC17-LFW joint with a complex micro-structure during the tensile processing, and predicted its mechanical properties and fracture behavior.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Mechanical Engineering Technology, College of Applied Industrial Technology, Jazan University, Jazan 45142, Saudi Arabia.
This paper estimates friction stir welded joints' ultimate tensile strength (UTS) and hardness using six supervised machine learning models (viz., linear regression, support vector regression, decision tree regression, random forest regression, K-nearest neighbour, and artificial neural network). Tool traverse speed, tool rotational speed, pin diameter, shoulder diameter, tool offset, and tool tilt are the six input parameters in the 200 datasets for training and testing the models.
View Article and Find Full Text PDFHeliyon
December 2024
Department of Mechanical and Construction Engineering, Northumbria University, Newcastle Upon Tyne, NE1 8ST, United Kingdom.
Aluminium-lithium (Al-Li) 2060 alloy, a 3rd generation Al-Li alloy, is considered a structural material for aircraft components. This study employs the Friction Stir Welding (FSW) process with a kinematic 5-axis robotic arm to weld 4-mm-thick plates of 2060-T8E30 Al-Li alloy. The focus is on the impact of tool axial force and speeds on the microstructural evolution, mechanical properties, and surface integrity of the welded joints.
View Article and Find Full Text PDFSci Rep
January 2025
Beijing Solidwel Intelligent Technology Co., Ltd., BeiJing, 100000, China.
Based on the Johnson-Cook constitutive model and modified Coulomb's law, the study investigates the impact of various process parameters on the weld temperature field in high-strength 5052 aluminum alloy friction stir welding (FSW) for aerospace applications. Utilizing a thermo-mechanical model, the significance of rotational speed, welding speed, and indentation on the peak weld temperature is examined through Taguchi's orthogonal experimental design. S/N ratio and ANOVA results show that the rotational speed has the most significant effect on the peak temperature of the weld, followed by the amount of indentation, and the welding speed has the smallest effect, the optimal combination of welding process parameters is determined as follows:the rotational speed is 1000 rpm, the amount of indentation is 0.
View Article and Find Full Text PDFSci Rep
December 2024
School of Reliability and Systems Engineering, Beihang University, Beijing, China.
Friction stir processing (FSP) is successfully employed to alleviate their hook defects of friction stir lap welding (FSLW) of aluminum alloys. The mechanical properties and microstructural characteristics are compared and analyzed between the FSLW&FSP joint fabricated by FSLW and FSP and the FSLW joint. The microstructural analysis shows that the hook defect zone at the advancing side of the FSLW joint is changed into the overlap zone (OZ) of the FSLW&FSP joint due to microstructure reconstruction caused by performing the FSP.
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