Corrosive effect of acrylic acid on magnetic head and media of an operating hard disk drive

Magnetic heads and media in a magnetic hard disk drive are often attacked by corrosive gases, such as hydrochloric acid, sulphur dioxide and acrylic acid, ect. In this paper, we investigate the corrosion progress of heads and media subject to contact-start-stop (CSS) operation under diluted acrylic acid vapor attack. It is found that under elevated temperature and humidity, acrylic acid vapor not only accelerates the magnetic hard disk media corrosion rate at carbon overcoat pinhole locations, but also induces new corrosion products such as cobalt acrylate and nickel acrylate. Different corrosion pattern at tribological contact area and non-contact area in an operating hard disk drive are observed and the related corrosion mechanism is discussed. This paper presents a view of corrosion products and corrosion progress at the different locations of magnetic heads and media under the diluted acrylic acid vapor attack in an operating hard disk drive.