How To design Part /product & How to design Moulding Tool | Door Handle mould design complete concept with animated series vise & Machine Working process.

 

RAW MATERIALS SELECTION:-

The selection of raw material plays a predominate role & it is an important criteria in tooling. At the same time improper selection may affect an adversely on many factors such as mould life, quality of mould, cost of the mould etc.

             The raw material used for this tool is steel. The raw material chosen for each part has its own function to perform. Raw  material  selected usually  depends on  the  functional  aspects  of  the  part  that  it  serves.

In general material selected should have the following characteristics:

1.           High resistance to heat.

2.           Sufficient toughness and hardness.

3.           Dimensional stability during heat-treatment.

4.           Good polishing properties. 

5.           High thermal conductivity.

Elements and their influence:

Carbon:

 Increase strength, elasticity and hardness.  It lowers the ductility and impact strength.  An  important  fact  is  that  above  0.3% carbon  the  steel  can  be  hardened  by  heating  and  quenching  in  water  or   oil.

 

Nickel:

 

Ø    Improves  toughness  and  wear  resistance  when  used  with            hardening  elements  like  chromium.

Ø    Gives fatigue resistance.

Ø    Greatly increases corrosion and oxidation resistance.

Ø    Usually less than 1% of   nickel used in alloy steel.

Ø    Increases harden ability.

Chromium:

 

Increases resistance and harden ability.  Additionally  relatively  large  percentage  of  chromium  greatly  increases  oxidation  and  corrosion  resistance.

 

Manganese:

 Manganese  also  serves  as  a  valuable  de-oxidizing  and  purifying  agent  Manganese  makes  the  metal  ductile  and  of  a  good  bending  qualities.  The  manganese  content  of  carbon  steel   is  usually  less  than  1%  and  commonly  ranges  from  0.3%-1%  .  Manganese  -di-oxides  contribute  to  strength  and  hardness  and   decrease  the  critical  cooling  rate.

 

Tungsten:

Ø    Increases wear resistance and red hardness property in the steel.  Tungsten forms strong carbide.  These  carbides  are  extremely  hard  ,wear  resistant  and  brittle  and  retain  hardness  at elevated  temperature  of  550  degree  Celsius.

 

Ø    Used for cutting tools.

 Ranges  from  0.25-1.5%  this  is  added  along  with  other  elements  to  improve  tensile  strength,  hardness  and  shock  resistance  of  castings.  Molybdenum   promotes harden ability.  Increases  tensile  and  creep  strength  at  high  temperature  it  has  both  the   properties  of  chromium  and tungsten.  About 5-20% molybdenum added for molybdenum based HSS tools

 DESIRED CHARACTERSTICS OF MOULD STEELS:-

¨  Structural soundness & un uniformity

¨   Good merchantability.

¨   High resistance to heat

¨    Sufficient strength & hardness to resist deformation

¨    Sufficient toughness to resist cracking

¨    High thermal conductivity

¨    Dimensional stability in heat treatment

¨    Low co-efficient thermal expansion

¨    Good polish ability.

THE RAW MATERIAL FOR TOOL CAN BE CHOSEN FROM THE FOLLOWING:-

¨     Steel

¨      Cast steel

¨       Brass

 CAST STEEL (CS-45):-

¨      Cast steel is also called as low carbon steels. These steels possess minimum tensile strength & have sufficient strength & toughness. It has excellent property of resistance. It is very cheap & can be easily machined.

 

¨      Parts which are manufactured in Cast Steel (CS-45) are:

  Top plate, Bottom plate, Spacers, Core plate, Cavity plate, Core back plate, Ejector plate & Locating ring.

OIL HADENED NON-SHRINKED STEEL (T110W2Cr1):-

            The cylindrical parts like ejector pins, , push back pins sprue puller etc. Guide bushes, Guide pillars, Ejector bushes & ejector pillars are manufactured in this material. Are some of the parts, which are manufactured from O.H.N.S. material. This material can be heat-treated & easily machined. It is wear resistance & has good mechanical properties. The chemical composition of this material is, 1.1% to 1.3% of carbon, 1% to 2% of tungsten, 0.35% to 1%chrnium etc. Hardness is 48-50 HRC.

COMPOSITION

¨     Carbon-0.9%

¨      Chromium-0.5%

¨      Manganese-0.4%

¨       Tungstun-0.5%

 17 MN 1 Cr 95 (CASE HARDNED STEEL):-

 The chemical composition of 17 Mn 1 Cr 95 materials is 0.17% carbon, 1% manganese & 0.95% chromium. These materials cannot be through hardened but can because hardened or carbonized. The core & cavity should be manufactured from the materials which posses the following properties:

¨                  High resistance to heat

¨                  Good machine ability

Sufficient toughness & hardness to resist deformation during operation.

HOT DIE STEEL (T35 Cr5 Mov1):- The name which includes the property of steel. The core & cavity is made up of H.D.S. material, this material having good resistance to thermal verification. During molding period heat & cools rapidly. This time the thermal stress is induced in the body. This behavior of material leads to cracking of material.  The H.D.S. is having a very good resistance to cracking of material & it is having a good dimensional stability when mould is heated.

·    The material used for core & cavity is T110 W2 CR1.

MILD STEEL (ST-42):-Mild steel is also called as low carbon steels. These steels possess minimum tensile strength & have sufficient strength & toughness. It has excellent property of resistance. It is very cheap & can be easily machined.

Parts which are manufactured in Mild Steel (St –42)