Olusanya, A (1998) The use of design of experiments techniques to determine the relative effectiveness of silane coupling agents on the durability of titanium alloy joints. A case study. NPL Report. CMMT(A)128

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Abstract

This report uses design of experiments (DOE) techniques to qualify the effect of silane coupling agents on the durability of titanium joints. This study is one of a series of durability case studies that will be used to demonstrate the use of the design of experiments analysis technique to quantify the interaction of the critical factors which give rise to environmental failure. The effect on the durability of titanium alloy joints was investigated for three epoxy adhesives and five surface pretreatments; grit-blasting, two types of silane treatment, sodium hydroxide anodising and catalytic etching. The data were sourced from the paper by Stone (DERA), [1] and permission was kindly granted to reproduce some of the data presented in that paper.
The main conclusions were:
· that grit-blasting gave a low durability for all the test adhesives examined.
· the silane pretreatments were more effective than grit-blasting only.
· anodising pretreatment gave the highest resistance to crack growth
The general trend was noted for the ranking of the pretreatments in the order of highest resistance to crack growth; Sodium hydroxide anodising >>> - - glycidoxypropyltrimethoxy silane ³ catalytic etching > - - aminopropyltrimethoxy silane > grit-blasting.
The comparison between the traditional approach, that is the graphical comparison of a variable which changes with exposure and an analysis based on design of experiments, which removes the influence of other variables from the analysis, has confirmed that the two methods yield similar results. What makes the DOE technique so useful is that it allows the researcher to rank the effects of a parameter and parameter inter-relationship on the process being investigated.
It must be stressed that this analysis is based on data from 1988, since then the technology and understanding of surface treatments has advanced due to an active collaborative research programme.
The effects of preparatory and application techniques on the relative effectiveness of silane treatments is under rigorous examination.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	CMMT(A)128
Subjects:	Advanced Materials Advanced Materials > Metals and Alloys
Last Modified:	02 Feb 2018 13:18
URI:	http://eprintspublications.npl.co.uk/id/eprint/2781

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