Fatigue Strength Characteristics Improvement and Weight Reduction of Structural Material for Automobile by Surface Reforming Treatment

2015 Fiscal Year Final Research Report

• Project/Area Number: 24560090
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: The University of Electro-Communications
• Principal Investigator: MATSUMURA TAKASHI 電気通信大学, 情報理工学(系)研究科, 准教授 (00251710)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 超高サイクル疲労 / 表面改質処理 / 軽合金

Outline of Final Research Achievements

The light alloys are promising as future structural material for the automobile. In this study, the fatigue strength characteristics in the very high cycle area, by the surface reforming treatments and by the variable amplitude are investigated. The each mechanism was grasped and the safety improvement in the fatigue strength characteristics is a purpose. From the results of this study, the fatigue strength of light alloys (Al alloy, Mg alloy) is improved in comparison with untreated test specimens and the light alloys was fractured by the fatigue in the very high cycle area. But, in the case that the surface of the specimen developed the roughness or the crack origin developed the inside in the very high cycle life area by the surface reforming treatments, the fatigue strength characteristics are not improved. From the results of the fatigue test by repeated two-step loading, in the testing conditions of this study, the linear cumulative damage rules of all tests were larger than one.

Free Research Field

機械工学