Materials Aluminium tooling: Applying the right alloy
USA – A focus on mould operating temperature and welding effects will help determine the right aluminium alloy for future mould builds. By Matt Kaye, vice president, sales and marketing from Clinton Aluminum, USA.
Use of aluminium tooling has been an ongoing discussion for years, and the resulting flow of information has been a key part of aluminium’s growth as a mould material alternative. This continuous growth has led to advances in mould alloys, material size availability, mould design, finishing practices, coatings and welding techniques. More and more success stories involving aluminium tooling are being shared, and this is essential in helping to ensure that future programs are designed and implemented with aluminium in mind.
Range of aluminium alloys for tooling
Most articles discussing the successes of aluminium tooling have been focused on 7xxx series aluminium alloys. Although these alloys have outstanding properties applicable to certain moulding applications, they are not always the most appropriate choice. Today there are a range of aluminium alloys available, and each has been used successfully for tooling in almost every industry, including automotive, medical, aerospace and consumer goods.
Characteristics influencing alloy choice include the material’s dimensional stability, part geometry, mould operating temperature and welding effects. This article will focus on the mould operating temperature and welding characteristics of a few alloy series.
Although many moulds are not exposed to higher temperatures, heat’s effect on a mould must be examined. If a mould (or a section of a mould) needs to handle temperatures ranging from 150°C to 200°C, then yield strength at room temperature may not be a deciding factor when choosing an alloy. Keep in mind that the following figures are typical and approximate, as variances may be seen among different materials.
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