ProSIM presentation GDC Tech 2015

www.pro-sim.com engineering your designs1

Survive or Succeed???

Dr S ShamasundarManaging Director, ProSIM

GDC-TECH 27th-28th Oct 2015 Pune


Simulated. Designed. Delivered.


Emerging Opportunity for GDC• Shifting from Sand casting to GDC

• Increasing emphasis on environmental issues becoming key in India

• Cost of sand reclamation increasing

• Increasing demand for engineered castings

• Increased acceptance of India as a major player in casting Industry ( India 3rd largest casting player, globally!!)


ProSIM- a Technology Collaborator• ProSIM has supported GDC companies to convert from Sand to

GDC.

• To develop gating systems in a faster and economical manner.

• To increase yield and reduce rejections

• To assimilate casting simulation technology in their design and development practice

• To develop process control maps by sensitivity analysis.


Air Entrapment in a brass gravity die castingcompared with ADSTEFAN simulation predicted results.


Fluid flow Analysis (Result Observation)

Pouring Temp- 1150Deg CLiquidus temp- 905 Deg CSolidus temp- 899 Deg C

Observation- when the die cavity filling is complete, there are regions with temperature well below the solidus temperature, hence hindering the melt flow.

In order to have uniform temperature distribution all around the cavity die preheat temperature should be increased. Intermediate connections are to be made such that molten metal flows to all the locations without temperature drop below the solidus temperature.

870°C


Analysis of melt flow in die cavity

Blue color - air in the componentTransparent color -complete liquid metal Green color - mixture of liquid metal and air

Observation - All the highlighted regions in the image are the potential locations for air entrapment. Which may lead to gas porosity defects.


Solidification Analysis of casting

Observation- The picture shows the final stage of solidification. The image shows the last regions of solidification embedded in the interior of casting.

Due to drop in temperature below solidus temperature, few regions have already solidified.

Shrinkage porosity will be formed in these regions.

Result interpretation-Fraction solid (Fs = 0) - Represents complete liquid metal Fraction solid (Fs = 1) - Represents complete solid metalBetween Fs= 0 and Fs=1, the color gradation shows a mixture of solid and liquid metal


Shrinkage porosity regions

The image shows the shrinkage present in the component. These shrinkages are due to lack of proper air vents.

The shrinkages are present all along the component surface as shown. Shrinkages present are of considerable volume.

In the physical casting, hundreds of sites of shrinkage porosity of various sizes were observed, as has been simulated using ADSTEFAN.


Summary• Existing gating design of gravity die casting of brass was

simulated using ADSTEFAN.• Key defects observed in trial casting – mainly air entrapment and

shrinkage were seen in the simulations as well.• Die preheat temperature should be increased establish uniform

temperature in melt within die cavity• Vents have to be provided at the suitable locations such that the

entrapped air escapes out to the maximum extent• Due to improper temperature distribution, few locations have

solidified even before the cavity fills up. Hence temperature equilibration is essential to attain directional solidification

• Surface porosities are present all over due to the above reasons.


MODIFIED DIE DESIGN

Several dozen of gating designs were explored using ADSTEFAN simulation.

What is indicated here is only an indicative change. Due to high speed

solvers present in ADSTEFAN, the design optimization was achieved in a

span one week.


Die details (with modifications)

Modified Die Cavity with Vent pins and connections

Vent Pins

Additional Connection (3 no’s)

Ø15mm Vent Pins (4 no’s)

Ø30mm Vent Pins (7 no’s)



Points to note-Pouring Temp- 1150Deg CLiquidus temp- 905 Deg CSolidus temp- 899 Deg C

Observation- at the end of die cavity filling, near uniform temperature distribution is observed throughout the component. Temperature is above solidus temperature.

902°C



Observation - All the highlighted regions in the Fig. are the potential locations for air entrapment.

Based on air entrapment locations & flow simulations, vent pin locations are finalized.

The entrapped air is expected to escape out through the vent pins.

Blue color - air in the componentTransparent color -complete liquid metal Green color - mixture of liquid metal and air


Solidification Analysis (Progressive solidification)

Observation-

The highlighted shrinkage locations are the locations of vent pins thereby taking care of shrinkage defects.

Result interpretation-Fraction solid (Fs = 0) - Represents complete liquid metal Fraction solid (Fs = 1) - Represents complete solid metalBetween Fs= 0 and Fs=1, the color gradation shows a mixture of solid and liquid metal


Shrinkage

• Shrinkage porosities are present but few mm (around 7.5-10mm) below the surface

Min depth is 7.5mm from this surface & 17mm from other surface

Min depth is 10mm from this surface and 15mm from other


Summary

• Pouring temperature and die preheat temp optimized using ADSTEFAN

• Vent pins location, size, and number were optimized using ADSTEFAN for air evacuation.

• Porosities were restricted internal locations at internal locations, 7.5mm below the surface. (which was acceptable to end customer in this case)


COMPARISON


902°C870°C

Temperature Distribution

Current Design Modified Design


Air Entrapment



Shrinkage



To Succeed

• Knowledge of material bahaviour• Casting Process• Gating design• Understanding of casting simulation technology• Background to SOLVE PROBLEM


ProSIM Can Help

You to succeed


High End Casting Simulation Software

Affordable. Usable. Profitable.


Die Temperature Analysis

Temperature distribution of die surface

More accurate fluid flow analysis is available by using the temperature distribution of the die, which is acquired from continuous casting.

Enable to acquire how many shots are required to be a steady state.

High pressure die casting simulation.

Die temperature analysis

Temperature Distribution inside of the Die

After 1st shot

Tem

pera

ture

(d

egC)

Unsteady State Steady State (from 4th shot)

Fluid flow analysis using this

temperature distribution

1 Cycle Elapsed Time (s)

After 10th shot


HPDC : Temperature in Molten Metal in shot sleeve

(1) Time from pouring start: 0.67s (Filled ratio: 50.5%)





(6) Time from pouring start: 1.7176s (Filled ratio: 100%)

[Condition 1] Pouring time: 1.7176s(Metal rising speed: 0.2&2m/s)


(1) Time from pouring start: 8.3s (Filled ratio:

43.8%)

Red: liquidus line temp. or overBlue: cessation of flow temp. or lower

(2) Time from pouring start:

9.0s (Filled ratio: 67.2%)

(3) Time from pouring start:

9.3s (Filled ratio: 80.6%)

(4) Time from pouring start: 10.1s(Filled ratio:

100%)

(Animation Display)

[Condition 1] Pouring time: 10s(Metal rising speed: 7cm/s)

LPDC : Temperature in Molten Metal in a wheel casting


Tilt Casting

Start from puddle filled with molten metal

Start from filling molten metal to puddle

Solidification analysis after tilt casting

Shrinkage Porosities

Total Elements: approx 0.75 millionPercentage of Casting Parts: approx 16%

Types of Analysis(1) Filling Analysis

(2) Solidification

Analysis Time: approx. 50min (Flow) approx. 5min (Solidification)

(Used PC: Xeon 3.6GHz)

Used Memory: 24MB (Flow) 25MB (Solidification)

・ Tilt Analysis・ Back-Pressure

Unsolidified

Solidified

High

Low


Centrifugal CastingAnimation Display Static Display

300rpm

100rpm

This model shows that timing to be filled of each part is changed by speed of rotation.

Total Elements: about 1.2 millionPercentage of Casting Parts: about 8%

Contents of Analysis

・ Filling Analysis (Centrifugal Analysis)

・ Thermal Analysis (Temp. Drop)

Analysis Time: about 2.8h

(Used PC: Xeon 3.6 GHz)

Used Memory ： 290MB


THANK YOU

For your casting simulation and gating design optimization needsContact:

[email protected]

ProSIM R&D Pvt. Ltd.,#4, 1st B Main, 1st N Block, Rajajinagar, Bangalore - 560010, India

Phone: +91-80-233 230 20 / 412 777 92-93

ProSIM presentation GDC Tech 2015

Engineering

Transcript of ProSIM presentation GDC Tech 2015