Post on 05-Jan-2016
description
Team Cleanweld, University of Idaho: Ken Bean, David Hewitt, Tess Howell, Nathan Jerred, Erik Shallman
Advisor: Dr. David Drown
May 1, 2009
Client Project Introduction• Prior Analysis and Scope
Objectives Stored Gas Inflator Wash Process Spectrometry and Microscopy Methods and Results Recommendations
Autoliv Inc. • A worldwide leader in automotive safety• Products include seatbelts, airbags, child
restraints, etc.• Products used by all major auto
manufacturers• Based in Brigham City, Utah
Stored Gas Airbag Inflator• Three-Step Cleaning Cycle
“Leakers” • Represent loss of product
Autoliv’s Prior Analysis• Inflators are leaking due to failing laser welds• Failures not caused by welding parameters• Failure possibly due to surface contamination
from the wash process Scope of Research• Focus on burst disk laser welds• Includes a study of weld surfaces and wash
process
Determine the effects of wash and rinse compositions on laser-weld failure• Identify surface contaminants present on
inflators• Explore existing failures to determine leak
rates• Examine the laser weld using optical
microscopy• Analyze the composition of the wash
detergent and rinse solutions• Recommend strategies to reduce weld
failures and operational costs
The Initiator The Diffuser
The Body
Inconel™ Disk
JenFab Drum Washer
Wash Rinse 1 Rinse 2 Dry
Wash Rinse + RP
Part Flow
SendSend ReturnReturn
Tap Water + RPWash Solution
HMS confirmed inflators were leaking Sniffer wand confirmed leaks from
initiator burst disks only
Part ID HMS Leak Rate
MAS VXA EF BET 7.78 E -04
NXG VXA EK EBM Too large to measure
NXG VXA EK ETW 5.73 E -06
NXC VX9 EK E1B Too large to measure
FCP VXA EX CHE Too large to measure
Two inflators tested: “As received” – taken directly off Autoliv’s
wash process assembly line“Clean” – washed in the lab with acetone
and ethanol Identified surface residue with EDS
analysis Compared the cleanliness of the
inflators
“As Received” “Clean”
Laser weld with Porosity Laser weld without porosity
Inductively Coupled Plasma (ICP)• Provides the elemental composition of the
solutions pH• Enable us to compare the basicity of the solutions
with their respective leaker data and draw important conclusion
Potassium Ion Selective Electrode (ISE)• Converts the activity of a specific ion dissolved in a
solution into an electrical potential which can be measured
Conductivity• In solution, current flows by ion transport.
Therefore, an increasing ion concentration in the solution will result in higher conductivity values
Further research suggestedCurrent data is inconclusive
Solution Monitoring MethodsConductivity and K-ISE viable methods
Counter Current Wash Modifications
Tap Water + RP
Waste WaterWash solutionDirty Rinse
JenFab Drum Washer
Autoliv Inc.Mark Bunker
Dr. David Drown Dr. Yanko Kranov Dr. Karl Rink Dr. Daniel Choi Branden Poulsen
Thank you for your attention.