Control of Deformation of Elastic Polymer-Abrasive Circles at their Wear

The article is devoted to the study of the wear intensity of elastic polymer-abrasive circles when processing the surfaces of parts made of high-strength aluminum alloys. Empirical dependencies of wear on cutting speed and tool deformation are obtained, on the basis of which method of tool deformation correction with long-term, continuous surface treatment is proposed. In practice, such a procedure is necessary due to the loss of process performance that occurs due to the reduction of tool deformation due to wear. The proposed technique allows to effectively control the finishing process as the tool is worn out.

Effect of vibrations on the residual stress field formation during milling of high-strength aluminum alloys

The authors examine the influence of high-speed milling on the distribution of residual stresses in parts made of structural high-strength aluminum alloys Al-Cu-Mg, which are the main structural materials in the aerospace industry. Milling was carried out at high cutting speeds. Different tool settings were used to balance the instrument. Plastic deformation occurred in the part’s surface layers. Residual stresses were measured by the X-ray method. It was found that high-speed milling creates residual compressive stresses that are favorable for the operation of the part. The depth of the residual stresses depends on the cutting mode. The article shows the relationship between residual stresses and the type of metalworking tool, processing conditions in structural parts made of high-strength aluminum alloys.

Chipping Reduction Using Thermally-Assisted Friction Element Welding

The use of multiple material in the structural components of a vehicle allows for significant weight reduction. Friction element welding (FEW) is a novel method that allows the joining of two or more dissimilar material sheets. A limitation of this process is the chip formation in high strength aluminum alloys, which is observed as the protrusion of thin aluminum segments from under the head of the fastener. Chipping can degrade the joint’s strength over time due to accelerated crevice corrosion. A novel method is proposed to eliminate chip formation using thermal assistance. A grading scheme is developed to quantify the severity of chip formation. The effect of thermal assistance on chipping is analyzed. An investigation is also carried out to validate that the thermal assistance does not negatively affect the process time, energy, and joint strength. Thermal assistance is proposed to be a novel method of overcoming this limitation to allow more widespread use of the FEW process for higher-strength aluminum alloys. Future work will include the development of feasible, rapid methods of heating and measurement of energy utilization for implementation in the industrial environment.

Conduction Heat Assisted Friction Element Welding

Increasing awareness of global warming and strict government regulations have required the automotive industry to pursue lightweighting as an avenue towards increased vehicle efficiency. Lightweight designs typically rely heavily on multi-material use, which enables selective strengthening of critical areas without additional, unnecessary mass. Joining these materials during manufacturing has proven to be a challenging endeavor. Friction element welding (FEW) is one process that is capable of joining aluminum to steel. This two-sided joining technique utilizes a fastener to secure the aluminum sheet by creating a friction weld with the steel sheet. While this process is extremely robust for most materials, the FEW process can result in the extrusion of material from underneath the head of the fastener, termed chipping, which leads to corrosion and aesthetic issues. This behavior is typically seen in high strength aluminum alloys, such as 7075. A solution to chipping is implemented herein, which utilizes a modified downholder to conductively heat the aluminum sheet prior to the FEW process. This heating method was explored experimentally and through various numerical analyses. This method was found to be a viable option for relieving chipping. While the process time was only increased by a maximum of 2.5 seconds, faster, more localized heating should be targeted for future work.

Applications of Aluminum Alloys in Rail Transportation

This chapter focus on the latest applications of aluminum alloys in rail transportation field. The typical high-strength aluminum alloys used on high speed train is introduced. The unique properties of aluminum alloys are analyzed. The detailed application is illustrated including car-body, gear box and axle box tie rod. The main challenges encountered in the application are also mentioned. The key manufacturing techniques, such as casting, forming, welding, are analyzed. Finally, the future improvement directions for better application is summarized. It is expected to set up a bridge for materials providers, equipment manufacturers and end-users, thereby promoting the advance of manufacturing technology and application of aluminum alloys in wider fields.