Evaluation of Bonding Strength in Urea Water Environment Between Wet-Treated SUS304 Stainless Steel and Polyphenylene Sulfide Resin

Abstract

This study investigates the feasibility of integrated injection molding using wet-treated metal surfaces. AMALPHA treatment, a wet process, achieves high bonding strength and airtightness, potentially reducing processes for molding urea water identification sensors in diesel vehicles. We explore the impact of wet processing on bonding interface shape, evaluating its effect on automotive sensor component hermeticity and durability. Joint strength tests were conducted on the AMALPHA treatment to infer the effect of surface conditions on fracture strength and the fracture process. We fabricated a prototype sensor component under conditions of sufficient bond strength and assessed its performance through testing. From the high-temperature urea water immersion test as a durability test, it was considered that urea water causes the formation of interface defects. An anchor shape by wet processing with sufficient durability as a joining method for actual sensors could be obtained.