Nicolae Panc

Comparative Analysis of Surface Finishing for Different Cutting Strategies of Parts Made from POM C

This paper focuses on the comparing the resulting surface after finishing holes machined with different cutting technologies. The machined material is Polyoxymethylene polymer POM C. The cutting technologies that were used are: helicoidal milling, contour milling, head boring, and reaming. The main purpose of this paper is to establish the most appropriate finishing technology for a hole, depending on its functional role. The article compares each finishing process following the qualitative differences that occur. Qualitative analysis refers to the dimensional, shape and quality precision of the obtained surface. Surface quality was evaluated through its main parameters: surface roughness and surface texture. Following the evaluation of the worked surfaces, it was found that there are considerable differences between the finishing strategies that were used. The differences are considerable enough that one should consider using one technology instead of another depending on the use case. The results of this paper help in making faster decisions about what finishing technology to use when finishing holes in a POM C part depending on the functional purpose of the machined hole.

How the Crystallization Process in Metal Casting is Influenced by the Mold Filling and Cooling Methods

The paper presents a case study on a aluminium part obtained by three different casting methods: die casting, investment casting and sand casting. The article analyzes the mold filling method, solidification time and crystal structure type obtained for each casting process. The purpose was to obtaine more homogenous crystalline structure of the cast parts, with better mechanical properties. The mold filling method with molten metal and heat transfer method influences the mechanical properties of the cast parts.

Evaluation of Overall Efficiency of Devices with Worm Gear

Overall efficiency represents an important qualitative property for devices used in manufacturing technology. This paper presents the mathematical modeling of calculating worm gear overall efficiency. The studied worm gear types goes into numerous manufacturing devices component. Mathematical model validation was experimentally performed on a tool sharpening device with a helicoidally profile. The analytical calculated results were closed to experimentally determined results, which partially validates the model proposed in the paper.

Using Simulation to Improve the Quality of the Metallic Industrial Components Made by Rapid Casting

Industrial parts with complex shapes are characterized by thin sections and complex geometries. Rapid vacuum casting is an ideal technology to manufacture complicated parts in small series production or prototypes. Contributions regarding simulation and analyzing of the parts made by rapid vacuum casting technology are presented in this study. Using dedicated software for simulating the casting process was analyzed and optimized the time of casting, the complete filling with material and also reducing the surface defects.

The Geometry Equations for Multiple Kinematic Structures Using Direct Geometry

In this paper are presented two kinematic structures able to move/rotate along/around tree axis each simultaneous. These two structures are restricted on a common fix bed and have the possibility perform a translational motion first and then to rotate along or around each axis. The equation used to describe the position and orientation of the first structure in relation to the second are then presented. Furthermore a reduction of the general case is made to prove the general mathematical model on a structure similar to a five axis turning and milling machine.