Additive manufacturing ka matlab hota hai “cheezon ko layer-by-layer banakar tayar karna.” Isse hum 3D printing bhi kehte hain. Isme material ko ek ek layer karke add kiya jata hai jab tak poori object ban nahi jaati. Ye traditional manufacturing (jisme material ko kaat kar ya ghis kar shape diya jata hai) se alag hoti hai.
Metal Additive Manufacturing ko hum do parts m divide kar sakte h –
- Powder Based Fusion (PBF)
- Direct Energy Deposition (DED)
🔹 Powder Bed Fusion (PBF)
Full naam: Powder-Based Fusion
Isme ek thin layer of metal powder bed pe bichhaayi jaati hai, phir laser ya electron beam se us powder ko melt karke solid banaya jaata hai. Ye process har layer ke liye repeat hota hai.
Steps:
- Powder bed me ek layer metal powder daali jaati hai.
- Laser ya beam sirf us area ko melt karta hai jahan part banana hai.
- Ek aur powder ki layer daali jaati hai, process repeat hota hai.
🛠️ Common technologies:
✅ Pros:
- High detail aur accuracy
- Strong & functional metal parts
- Ideal for aerospace, medical, etc.
🔹 Directed Energy Deposition (DED)
Isme metal powder ya wire ko ek nozzle se directly deposit kiya jaata hai, aur usi time laser, electron beam ya plasma arc us material ko melt kar deta hai.
Steps:
- Nozzle se wire ya powder aata hai.
- Saath hi laser/beam se melt hota hai.
- Material turant deposit aur solidify hota hai.
🛠️ Common use:
- Large industrial parts
- Part repair (like turbine blade repair)
- Hybrid CNC + 3D printing machines
✅ Pros:
- Existing metal parts pe material add kar sakte ho (repairing)
- Fast deposition rate
- Suitable for large & strong components
🚩 Difference at a Glance:
| Feature | Powder Bed Fusion (PBF) | Directed Energy Deposition (DED) |
|---|---|---|
| Material form | Fine powder in a bed | Powder or wire from a nozzle |
| Energy source | Laser / Electron Beam | Laser / Electron Beam / Plasma |
| Use case | High precision parts | Large parts, repairs |
| Surface finish | Better finish, high accuracy | Rougher finish, post-processing needed |
| Speed | Slower | Faster |
Powder Based Fusion ko hum 3 parts m divide kar sakte h –
- Selective Laser Melting (SLM)
- Direct Metal Laser Sintering (DMLS)
- Electron Beam Melting (EBM)
🔹 1. SLM (Selective Laser Melting)
- Working:
Ek high-power laser se metal powder ko completely melt kiya jaata hai. - Material:
Pure metals ya alloys (jaise titanium, aluminum, stainless steel). - Result:
Part bilkul solid banta hai, koi porosity (chhed) nahi hoti.
✅ Pros:
- Strong, dense parts
- Good for aerospace, medical, automotive parts
❌ Cons:
- Thoda complex materials ke liye challenging ho sakta hai
🔹 2. DMLS (Direct Metal Laser Sintering)
- Working:
Laser se metal alloy powder ko sinter kiya jaata hai, yaani powder ko high temp par stick karte hain, but completely melt nahi karte (partial melting). - Material:
Alloy powders (multi-element metals)
✅ Pros:
- Better for complex alloy materials
- Thoda flexible process
❌ Cons:
- Part thoda porous ho sakta hai, post-processing zaruri hoti hai
- Density SLM se thodi kam hoti hai
Animation of DMLS – Click Here
🔹 3. EBM (Electron Beam Melting)
- Working:
Electron beam (instead of laser) vacuum chamber me metal powder ko melt karta hai. - Environment:
Vacuum required (oxygen-free) - Material:
High-temp alloys, jaise titanium, Inconel
✅ Pros:
- Very strong parts
- Less residual stress (thermal stress kam hoti hai)
- Fast melting for large parts
❌ Cons:
- Surface finish rough hoti hai
- Only conductive materials (electron beam ke liye zaruri)
- Setup mehenga aur complex hota hai
🔍 Comparison Table:
| Feature | SLM | DMLS | EBM |
|---|---|---|---|
| Energy Source | Laser | Laser | Electron Beam |
| Powder Melting | Fully melted | Partially sintered | Fully melted |
| Environment | Inert gas (Argon/Nitrogen) | Inert gas (Argon/Nitrogen) | Vacuum |
| Materials Supported | Pure metals & alloys | Alloys | Conductive alloys (e.g. Ti) |
| Surface Finish | Smooth | Medium | Rough |
| Density of Part | High (solid) | Medium to high | High |
| Build Speed | Moderate | Moderate | Fast |
| Application | Aerospace, medical, tools | Complex alloys, prototypes | Aerospace, implants |