High Temperature-Creep Resistant Magnesium Alloys:Advances in Thixomolding Automotive Components

Paper #:
  • 2000-01-1126

Published:
  • 2000-03-06
Citation:
Nyberg, E., Jones, R., Pitman, S., Carnahan, R. et al., "High Temperature-Creep Resistant Magnesium Alloys:Advances in Thixomolding Automotive Components," SAE Technical Paper 2000-01-1126, 2000, https://doi.org/10.4271/2000-01-1126.
Pages:
10
Abstract:
Applications of magnesium-based alloys to transmission and underhood automotive components have been limited by creep and bolt-load relaxation. A further concern is the relative expense of Mg alloys, such as AE42, that contain rare earth elements. These alloys still fall short of the performance of 380 Al. A new family of low-cost Mg alloys (ZAC) containing Zn, Al, and Ca has been developed and reported to approach AE42 and to outperform 380 Al; however, it exhibits castability concerns in die casting.This study was designed to evaluate the performance of semi-solid injection-molded (Thixomolded®)1 ZAC8506 bolt-load retention samples at temperatures up to 175°C. The Thixomolding® process has been reported to markedly improve the creep resistance of AZ91D as the volume fraction of solids is increased. The processing conditions were selected to produce bolt-load retention samples having solid fractions of 6% to 37% primary alpha. The bolt-load retention properties were then studied as a function of time at a torque level of 28 kN and at 150 and 175×C for periods of 100 h.The study also included both Thixomolded and die cast AZ91D bolt-load retention samples for direct comparison, and corroboration of the test methodology for bolt-load retention. Elevated temperature measurements of both tensile and compressive properties were also carried out on the ZAC8506 alloy. The moldability of ZAC was evaluated using a relatively complex Delphi automotive electronics housing.
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Select
Price
List
Download
$27.00
Mail
$27.00
Members save up to 40% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Standard
2011-08-04
Training / Education
2017-10-19
Article
2017-03-13
Training / Education
2017-10-23