Appunti di tutte le lezioni del corso Advanced Manufacturing Processes

Introduction

Growth/productivity decline in last 50 years:

Big growth from 1st manufacturing revolution

• I 1850 ➔ Steam engine (replace energy)
• II 1900 ➔ Mass production models (Ford)
• III 1970 ➔ Automation
• Manufacturing revolution ➔ Advanced robots
• AM ➔ More parts in one
• Change location, role and mode of work (service-based)
• Technology ↑ Displace productivity
• Cons ↑ Energy consumption
• Adaptability (res) flexibility ↑ Automation
• Models ➔ Advanced = specification, precise, non-traditional size, not always new (restat)
• Different form of energy: manual, mechanical, chemical/reactive

Chemal, ACL, EDM, WJT, FDM & bound setting PBF, DED

New and advanced materials (ceramic, carbon fibre...)

New or difficult products ➔ New parts, minimization size tolerance, easier assembly

Tools fixed at step ➔ Reduce tool setup cost and times (new technology and technique)

Better ➔ It's an intersection (3 skills) to finish products and process

Phenomenon ➔ Reality

Model ➔ Dimension

Formula

A tooth psi a coin, tooth fairy

Introduction

Growth/productivity decline in the last 50 years:

3 big growth from big manufacturing innovations:

• I 1850 = steam engine (create energy) → Huge productivity ↑
• II 1900 = mass production model (Ford) → ↑ mpr
• III 1970 = automation
• IV manufacturing revolution → Advanced robots

AM → More parts in one → Huge optimization ↑

Op ktop → Multiple factors eos → Flexibility, more personal

Ts convert market, ts re-based → Permanent

Technology ↑ Different productivity (factor?) flexibility cons (cheap?) automation different/lll (leis) models

Advanced = innovation, higher, non-traditional, not always new (exist)

Different form of energy, human mechanics, chemical/reactive

Casting, AL, EDM, GWT, FDM → 6 bound setting PBF, DED

→ New and advanced materials (ceramic, carbon fiber...)

→ New on difficult products → Few parts, minimization, higher tolerance, easier

→ Iocaa fixed at xtep tolerance

→ Cost and times new technology and skills better

It's an integration (is still) to finish production and process

Phenomenon reality → Model = ambition → We need theoretical knowledge → Unique reference model or and part of process

→ Mathematical model → Physical model

→ Formal → "Black box" → Empirical model

Unique specific moase original or rational to code

Thermal model

Heat transfer = temperature difference

Fourier law

Conduction

q''_x = -k dT/dx

k - thermal conductivity [W/mK]

Newton law

Convection

q'' = h (T_s - T_∞)

h - convection coeff [W/m²K]

Assumptions

• K constant - k = k(T) NO
• Isotropic and homogeneous material
• Control volume, temporal element

Energy balance / thermodynamic law

E_in + E_p - E_out = E_st

G_x is flow of energy

d²T/dx² + d²T/dy² + dT/dt = 1/α dT/dc

α - thermal diffusivity [m²/s] = k/(ρc_p)

T(x,t) - 1D unsteady heat flow - 1D unsteady ∂(T/∂t)

Material heat source weak internal heat

Type: 1D constant

Isotropic and homogeneous material

Same thermal and chemical property of material

No internal heat source

1D semi infinite geometry - D x

Pure conduction - no convection or radiation

T(x,t) = θ - solution: heat flow ρ⁰ across finite t

τ(x, t) = q⁰ √(4αt) erfc(x/√(4αt)) + T_i

erf - integral of normalized Gaussian function

erfc - complementary error function

ierfc - integral of complementary error function

D = √(4αt) thermal distance experiment material differentiated by heat source

Laser

6 basic laser manufacturing companies are the top 10 revenue Co. in Europe and 5 in the top 10 machine tool companies in Italy

50% market occupied by fiber laser

Laser systems revenue is about 5-10 times laser source revenue

1960 first laser public demonstration in 004 range but there are 2 variables laser invisible and modern RCL#[?]

Cutting, welding, marking, heat treatment