Automated surface finishing of plastic injection mold steel with spherical grinding and ball burnishing processes

Abstract

This study investigates the possibilities of automated spherical grinding and ball burnishing surface finishing processes in a freeform surface plastic injection mold steel PDS5 on a CNC machining center. The design and manufacture of a grinding tool holder has been accomplished in this study. The optimal surface grinding parameters were determined using Taguchi's orthogonal array method for plastic injection molding steel PDS5 on a machining center. The optimal surface grinding parameters for the plastic injection mold steel PDS5 were the combination of an abrasive material of PA Al 2 O 3 , a grinding speed of 18 000 rpm, a grinding depth of 20 µm, and a feed of 50 mm/min. The surface roughness R a of the specimen can be improved from about 1.60 µm to 0.35 µm by using the optimal parameters for surface grinding. Surface roughness R a can be further improved from about 0.343 µm to 0.06 µm by using the ball burnishing process with the optimal burnishing parameters. Applying the optimal surface grinding and burnishing parameters sequentially to a fine-milled freeform surface mold insert, the surface roughness R a of freeform surface region on the tested part can be improved from about 2.15 µm to 0.07 µm.

Characterization of Surface Integrity Produced by Sequential Dry Hard Turning and Ball Burnishing Operations

“…An interesting proposal of using the spherical AI2O3 grinding tool to perform grinding and tungsten carbide ball to carry out burnishing operations on a free-form workpiece on a CNC machining centre was given by Shiou et al in Refs. [11,17]. As a result, the surface roughness produced on a PD55 (AISI P20) mould steel of 33 HRC by fine milling was reduced from 1.6/¿m to 0.35 ^m by surface grinding and down to 0.06 ßm by ball burnishing.…”

Optimization of Ball Burnishing Process on Tool Steel (T215Cr12) in CNC Machining Centre Using Response Surface Methodology

“…The surface roughness Ra of the specimen could be improved from about 1.60 to 0.35 µm by using the optimal parameters for surface grinding. Surface roughness Ra can be further improved with the optimal ball burnishing parameters from about 0.343 to 0.06 µm [4]. Paiva et al have proposed a hybrid approach, combining response surface methodology (RSM) and principal component analysis (PCA) to optimize multiple correlated responses in a turning process [5].…”

Ultra-precision surface finish of the hardened stainless mold steel using vibration-assisted ball polishing process

“…The design and manufacture of the spherical grinding tool and its alignment device, and the optimal grinding parameters for mold steel, have been determined and shown in Ref. [11]. The design and manufacture of the slurry circulatory system, and a polishing tool including a high-speed grinder mounted with a felt ball and its holder, have been accomplished and shown in Ref.…”