400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 2001-01-0818 The Effect of Porosity Size on the Fatigue Properties in a Cast 319 Aluminum Alloy James M. Boileau an d John E. Allison Ford Motor Company Scientif ic Research Laboratories Reprinted From: Light Metal Appl ications for the Automotive Industry: Aluminum and Magnesium (SP–1622) SAE 2001 World Congress Detroit, Michigan March 5-8, 2001Downloaded from SAE International by Big Ten Academic Alliance, Wednesday, August 01, 2018The appearance of this I SSN code at the bottom of this page indicates SAE’s co nsent that copies of the paper may be made for personal or internal use of spec ific clients. This consent is given on the condition, however, that the copier pay a $8.00 per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec-tions 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such ascopying 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. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright 2001 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 whic h discussions will be printed with the paper if it is p ublished 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 c onsidered for presentation or publication thr ough SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in theGlobal Mobility DatabaseDownloaded from SAE International by Big Ten Academic Alliance, Wednesday, August 01, 20181 2001-01-0818 The Effect of Porosity Size on the Fatigue Properties in a Cast 319 Aluminum Alloy James M. Boileau and John E. Allison Ford Motor Company Scientif ic Research Laboratories Copyright © 2001 Society of Automotive Engineers, Inc. ABSTRACT A study was conducted to determine how the fatigue life of a 319 aluminum alloy (W319) was affected by poresize. To perform this study, two sets of microstructurallysimilar castings with differin g levels of microporosity were created. Following room temperature fatigue testing, thepores that initiated fatigue cracks were identified andquantified. The results indicate that doubling the averageinitiating pore diameter yielded an approximate 30%decrease in run-out stress in the W319-T7 aluminumalloy. INTRODUCTION In response to consumer demands for increasedperformance and fuel economy, the use of aluminum inthe automotive industry has grown dramatically in recentyears. Specifically, many components traditionally madefrom cast iron have been redesigned to allow the use ofcast aluminum. This is done to capitalize on aluminum’slower density; for example, a cast aluminum V-8 engine block can weigh up to 45% less than its cast iron counterpart. As a result, the automotive use of aluminum has greatly expanded. Currently, Ford is using over 7.5 million cast aluminum cylinde