Engineering students at Purdue University recently presented their senior-year project work in a poster session. One such poster was titled “Effects of Almen Strip Thickness on Shot Peening Attributes.” The participating students are Garrett Behrje, Ryan Carr, Ryan Siu, Chong Guan Teo, and Jack Vanbenthuysen. The faculty advisors are David Johnson and Mark Gruninger. The industrial sponsors for this project are Electronics Inc., Progressive Surface, American Axle & Manufacturing, and Cummins.
Almen strips, which are made of 1070 steel, are crucial for many industries including automotive and aerospace. There are three thicknesses (0.031″, 0.051″, and 0.094″) for Almen strips that are used and are labeled as N, A, and C, respectively. We seek to validate current industrial standards of intensity for the A strip (4A to 24A) and investigate functional differences of the Almen strip types including mechanical behavior, stress, hardness and how it relates to microstructure. Measurements of deflection will be taken on all types of Almen strips using fixed locations on an Almen gauge.
Based on our findings, we suggest the following before putting our work into practice.
• We were able to validate the finite limits for the A strip of 4A to 24A.
• We need to conduct further testing outside the region of 4A to 24A to observe similar trends for the N and C type strips. This in turn will allow us to propose finite limits for these strips.
• Complete hardness testing at lower and higher loads than performed to see if there is an effect from the surface or the elastic core made by the indenter.
• Conduct SEM images at a larger scale so that the impression is in the image to see if there are shape or size differences between trials.
Download the complete poster here.