Spinning-punch new technology for aluminum alloy plate-wheels forming
The aluminium alloy plate-wheels are a new kind of wheels with light-weight, energy-saving and environmental protection. Spinning is a conventional technology to form aluminium alloy plate-wheels, but the outline dimension and run-out of rolled lip in end face are difficult to meet the exacting requirements of wheels blueprint. So the new spinning-punch forming technology for aluminium alloy plate-wheels was researched and simulated. 3-D elastic-plastic finite element models were constructed and appropriate boundary conditions were given out. The results show that aluminium alloy plate-wheels with good quality can be formed by spinning-punch forming technology through controlling roller feed rate, roller'diameter, flanging times, and punching stroke, etc. And the relationships between spinning load and roller'diameter, rolled lip forming quality and flanging times are found.
An investigation of predictive control for aluminum wheel casting via a virtual process model
Abstract An advanced control solution, specifically Model-based predictive control (MPC), has been developed for a low-pressure die casting (LPDC) process used to manufacture aluminum alloy wheels. The control solution was developed offline using a high-fidelity 3D finite element model as a virtual process on which open and closed loop trials were performed. Open loop trials were used to assess the influence of process variables and to facilitate the development of a reduced-order state-space model to predict the approximate input–output behaviour of the casting process. An MPC controller employing this state-space model was used to regulate die temperatures in the virtual process during disturbance scenarios. Two disturbances typically found in the industrial process were simulated, that is, the temperature behaviour of the molten metal in the industrial process and the length of time the die remains open after the cast wheel is ejected from the dies. These disturbances cause the die temperatures to deviate from their optimal values, which can result in defective wheels. The developed control solution improved the process performance by rejecting the simulated disturbances and maintaining the die temperatures near their optimal values.
Stress-corrosion cracking susceptibility of various product forms of aluminum alloy 2519
Aluminum alloy 2519 is the main structural alloy for the Advanced Amphibious Assault Vehicle (AAAV). A potential drawback to the use of 2519, particularly for an amphibious vehicle, is its susceptibility to corrosion. General corrosion, which is largely in the form of pitting, may reduce the effective life of the system, while stress-corrosion cracking (SCC) of any high strength aluminum alloy can lead to catastrophic failure. Therefore, an evaluation of the SCC susceptibility of various 2519 product forms was performed. Plate, extrusions, ring roll forgings, and weldments all exhibited excellent SCC resistance as measured by a series of standard ASTM tests. Multi-axis hand forgings were the only product forms that exhibited SCC susceptibility, and this susceptibility was remedied via the use of a specifically designed heat treatment. While all product forms passed the prescribed SCC tests, each exhibited a significant reduction in strength after simultaneous exposure to both stress and the saline corrosion environment. Such behavior was not apparent when the exposure was limited to the corrosion media alone. That is, while resistant to SCC, the load-bearing capacities of all products tested are somewhat degraded during concurrent exposure to stress and corrosive media by a mechanism that includes pitting. This article will discuss the effort that was conducted by the National Center for Excellence in Metalworking Technology (NCEMT) to evaluate the SCC susceptibility of 2519 in various product forms and tempers.