SA E TECHNICAL PAPER SERIES The Compatibility of Magnesium Alloys with Automatic Transmission Fluids Kimberly Gaw, David Hawke, and Thomas Ruden Hydro Magnesium Marketing Reprinted from: Attributes of Magnesium for Automobile Design The Engineering Society A=For Advancing Mobility and Sea Air and Space- lnternationaf Congress & Exposition Detroit, Michigan February 28-March 3,1994 400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (41 2)776-4841 Fax:(412)776-5760 Downloaded from SAE International by University Of Newcastle, Thursday, August 09, 2018The appearance of the ISSN code at the bottom of this page indicates SAE's consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on thecondition, however, that the copier pay a $5.00 per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01 923for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department. To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. G~BAL MOglUTY DATABASE All SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility Database. No part of this publication may by reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. ISSN 0148-7191 Copyright 1994 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Activity Board, SAE. Printed in USA 80-1203~1~0 Downloaded from SAE International by University Of Newcastle, Thursday, August 09, 2018ABSTRACT The Compatibility of Magnesium Alloys with Automatic Transmission Fluids Kimberly Gaw, David Hawke, and Thomas Ruden Hydro Magnesium Marketing The compatibility of magnesium die casting alloys with commercial automatic transmission fluids was studied in laboratory tests. The effects of high temperature, presence of water, and galvanic coupling with steel were examined, using visual observation, weight change, Scanning Electron Microscope, and Scanning Auger Microprobe surface analysis. No significant corrosion of magnesium was detected under any of the test conditions. INTRODUCTION Magnesium die castings have contributed substantially to weight reduction in automotive powertrains. Alloys are available with improved resistance to creep and stress relaxation as required by operating temperatures up to 300°C. An important application in this category is the automatic transmission housing. Success in this application requires that the magnesium alloy be resistant to corrosion or chemical attack by commercial automatic transmission fluids (Am). Although magnesium is inert to unmodified petroleum oils, there are two possible mechanisms for corrosion by ATE (1) Reaction with an additive containing an active hydrogen atom,