Studying effect of triethanolamine in lubricant for using in lapping slider head process

Abstract

A problem in lapping slider head process in hard disk drive industry is spending a long lapping time leading to slow production. Therefore, slider fabrication development group of Western digital Co, Ltd has been interested in studying on some additives in lubricant using in lapping process to decrease lapping time. The research found that triethanolamine (TEA), one of the additives in ethylene glycol (EG) base stock helps reduce lapping time. Hence, this project studied on an effect of TEA in lapping process. The experiments were divided into 4 parts. The first part of experiment was testing physical properties of lubricants. The second part, experiments were done by using stripe slider bars in lapping and dipping with lubricants containing 0%, 3%, 6% and 10%wt. of TEA in EG. The third part, alumina titanium carbide (AlTiC) coupon coated with amorphous alumina as representative of major component in slider bar were dipped in 6%wt. of TEA and then characterized by optical microscopy, atomic force microscopy (AFM) and roughness test. The fourth part was study on the chemical reaction of solid alumina and TEA and characterization with Raman and 1H-NMR spectroscopy. Furthermore, the study on effect of TEA on cobalt-iron alloy which is minor component of slider bar was done by using potentiodynamic polarization technique. The results showed that TEA can reduce lapping time by removing alumina part of slider bar by Al-TEA complex formation.