Surface Waviness Controlled Grinding of Thin Mold Inserts Using Chilled Air as Coolant

Abstract

The ongoing trend of miniaturization in electronic related parts, which is an average of two times every 5 to 7 years, introduces machining challenges. Surface grinding of thin miniature parts is an ardent task due to its warpage, induced by high specific grinding energy (10–100 J/mm3). Therefore, coolant is used to avoid thermal damage, improve surface integrity, and prolong wheel life. However, coolant, the incompressibility media, introduces high forces at the grinding zone, that create dimensional and shape instability. This article presents the results of a new grinding method when using chilled air as coolant media for thin mold insert, two-stage vapor compression refrigeration cycle was adopted for production of chilled air of temperature, −35°C; pressure, 0.2–0.3 MPa; and flow rate, 0.4 m3/min. Along with chilled air, traces of vegetable oil mist was also impinged to the grinding zone. Both chilled air and vegetable oil mist were applied through two independent paths of a specially designed twin compartment nozzle for maximizing the penetration.