29719 - Mechanical Manufacturing Processes

Learning outcomes

The student acquires competences on materials and their mechanical and  technological properties  studying the main transformation processes. and  heat treatments. Will be acquired the knowledge of the main manufacturing processes, of physical phenomena to the base of their application and of the criteria for their choice; in particular the skills acquired will cover the processes for chip removal: roughing, finishing and finishing in tolerance. They will be acquired skills on the machines and equipment relating to the different processes and their conditions of use. The student acquires the knowledge of the foundry processes for the production of raw, semi-finished and finished components.Competences  will acquired also in the field of the plastic deformations processes with particularly references on the stress-deformation state of the materials to determine the correct application of the processes themselves. The student acquires powers to the processes of joining and in particular of welding.

Course contents

Mechanical Technology and product manufacturing. The quality of the worked surface: Dimensional and Geometric precision, the tolerances criteria; Micro and macro errors: roughness, shape errors and they measures; Relations between tolerances, roughness and processes. The graphical representation of the product. The manufacturing drawings              

The Materials for product manufacturing. The mainly usable materials for manufacturing. They classifications. The characterization of the materials: physical-chemical, mechanical, technological properties. The mechanical tests of the materials. The Ferro-Carbon Alloys. The metallurgical processes for their production. Steels, definition and classification, the main special steels and their applications. The main heat treatments for steel. Cast irons, Copper alloys, Aluminium alloys.             

Technological processes for product manufacturing. Processes description and classification, process selection criteria

The chip Removal processes. Description and Classification, physical bases of the cutting process, cinematic of the cutting process, the cutting parameters; geometric properties of the cutting edges of the tools, the theoretical roughness. Chips typology.  Pijspanen Model for cutting representation. The mechanics of the cutting process: the forces that act in the cut. Theories of Ernst-Merchant and Merchant modified. The cutting forces and power by the evaluation of the cutting pressure and the specific pressure. The thermodynamic in the cutting process. Tools materials and their operating characteristics, ware and life of the tools. Economic aspects of the cutting process. Machine Tools: Classification, structures and components of Machine tools. Conventional and to Numerical Controlled Machines. The principles of the CNC Control.

The main Removal processes and machines:

• Turning: classification of turning operations, tools characteristics, technological parameters; cutting forces and power, cutting times. Turning Machine: conventional lathes, CNC lathes, CNC turning Machining Centres.

• Drilling: drilling operations by helicoidally tools. Tool geometry. Drilling technological parameters, working times and cutting forces and power. Drilling Machines: from conventional to CNC machines. Deep drilling: tools and machines.

• Boring: The boring operations: tools and machines. The obtainable precisions.

• Milling. Milling operations: plane peripheral up and down milling; face milling, contouring milling.  Tools shapes and geometrical properties. Milling technological parameters, cutting forces and power, working time's calculation. Milling vertical and horizontal conventional machines. CNC milling Machine provided with 3, 4, and 5 simultaneous controlled axes, CNC Machining Centres.

• Grinding: cylindrical internal and external grinding. Centerless grinding. Surface grinding.  The grinder wheel tools. The technological parameters and the obtainable precisions. Conventional and CNC Machines.

The process plan: purpose and objects of the working cycle; criteria and procedures for developing a process plan. The technological data bases and data sheets to prepare a process plan. Tools presetting and tools sheet for machines setting-up. Working time and cost calculation. Examples of development of process plans.

Readings/Bibliography

Lessons Notes

 

Consultation Books

 

R. Levi, A. Zompì

TECNOLOGIA MECCANICA- Lavorazioni ad asportazione di truciolo

UTET

 

R. Levi, A. Zompì

TECNOLOGIA MECCANICA- Lavorazioni per deformazioni plastiche

UTET

 

Autori Vari

MANUALE DELLA FONDERIA

Tecniche Nuove

 

F.Giusti, M.Santocchi

E STUDI DI FABBRICAZIONE

Editrice Ambrosiana – Milano.

 

Fortunato Grimaldi

CNC MACCHINE UTENSILI A CONTROLLO NUMERICO

Hoepli

 

 

Teaching methods

Lessons and exercises

Assessment methods

The final test will be a write work followed by an oral talk

Teaching tools

The slides used in the course will be provided to the students

Office hours

See the website of Giovanni Tani

See the website of Luca Tomesani