Three Principles of Mold Material Selection

(1) Mold meets working conditions

 

  1. Wear resistance

 

When the billet is plastic denatured in the cavity, it flows and slides along the surface of the cavity, resulting in severe friction between the surface of the cavity and the billet, which leads to the failure of the mold due to wear. So the wear resistance of materials is one of the most basic and important properties of dies.

 

Hardness is the main factor affecting wear resistance. Generally speaking, the higher the hardness of mold parts, the smaller the wear amount and the better the wear resistance. In addition, the wear resistance is also related to the type, quantity, morphology, size and distribution of carbides in the material.

 

  1. Strength and tenacity

 

Most of the working conditions of the mold are very bad, and some of them often bear large impact load, which leads to brittle fracture. In order to prevent the sudden brittle fracture of mold parts, mold should have high strength and toughness.

 

The toughness of the mold mainly depends on the carbon content, grain size and structure of the material.

 

  1. Fatigue fracture properties

 

During the working process of the mold, fatigue fracture often occurs under the long-term effect of cyclic stress. Its forms include low energy multiple impact fatigue fracture, tensile fatigue fracture, contact fatigue fracture and bending fatigue fracture.

 

The fatigue fracture performance of the die mainly depends on its strength, toughness, hardness and inclusion content in the material.

 

  1. High temperature performance

 

When the working temperature of the mold is higher, the hardness and strength will decrease, leading to early wear or plastic deformation of the mold and failure. Because the mold material should have high tempering stability to ensure that the mold has high hardness and strength at working temperature.

 

  1. Cold and thermal fatigue resistance

 

 

Some moulds are in the state of repeated heating and cooling in the working process, which causes the surface of the cavity to be tension and pressure variable stress, causes surface cracking and peeling, increases friction, hinders plastic deformation, reduces dimensional accuracy, and leads to mold failure. Thermal and cold fatigue is one of the main failure modes of hot-working mold, which should have high cold and thermal fatigue resistance.

 

  1. Corrosion resistance

 

When some moulds such as plastic moulds are working, due to the presence of chlorine, fluorine and other elements in the plastics, strong corrosive gases such as HCI and HF are decomposed and precipitated after heating, which erode the surface of the mould cavity, increase its surface roughness and aggravate the wear failure.

 

 

(2) Mold meets process performance requirements

 

Mold manufacturing usually goes through forging, cutting, heat treatment and other processes. In order to ensure the manufacturing quality of the mold and reduce the production cost, the material should have good malleability, cutting machinability, hardenability, hardenability and grindability, and should also have small oxidation, decarbonization sensitivity and quenching deformation cracking tendency.

 

  1. Forgetability

 

It has low resistance to hot forging deformation, good plasticity, wide forging temperature range, low tendency of cold cracking and precipitation of network carbides.

 

  1. Annealing Processing

 

The spheroidizing annealing temperature range is wide, the annealing hardness is low and the fluctuation range is small, and the spheroidizing rate is high.

 

  1. Machinability

 

Large cutting parameters, low tool wear, low surface roughness.

 

  1. Sensitivity of oxidation and decarbonization

 

When heated at high temperature, it has good antioxidant capacity, slow decarbonization speed, insensitive to heating medium and little tendency to produce pitting.

 

  1. Hardenability

 

After quenching, it has uniform and high surface hardness.

 

  1. Hardenability

 

After quenching, a deeper hardening layer can be obtained, and it can be hardened by using a mild quenching medium.

 

  1. Cracking Tendency of Quenching Deformation

 

The volume change of conventional quenching is small, the shape warpage and distortion are slight, and the tendency of abnormal deformation is low. Conventional quenching has low cracking sensitivity and is insensitive to quenching temperature and workpiece shape.

 

  1. Grindability

 

The relative wear of grinding wheel is small, the limit grinding amount without burn is large, and it is insensitive to the quality of grinding wheel and cooling conditions, so it is not easy to cause grinding damage and grinding cracks.

 

(3) Mold meets economic requirements

 

In the selection of mold materials, the principle of economy must be considered to reduce the manufacturing cost as much as possible. Therefore, on the premise of meeting the service performance, the first choice is low price, carbon steel can be used instead of alloy steel, domestic materials can be used instead of imported materials. In addition, the production and supply situation of the market should also be taken into account when selecting materials. The selected steel grades should be as few as possible, concentrated and easy to purchase.

 

JasonMould Industrial Company Limited, established in 2010, is a leading China mold factory. JasonMould specializes in plastic mould production for household appliances, medical equipments, electronic equipments, safety equipments as well as monitoring system.

The company has over 15000 square metres factory. With plastic injection tooling divisions possessing different machinery and expertise, JasonMould offers tools from small and precise mobile phone parts to as big as automotive parts. Our tools are mainly exported to U.S.A., Europe, Japan and UK. JasonMould’s diversification strategy and full service has won compliment from customers all over the world.

Our mission is to provide our customers high quality moulding products and services. We aim to exceed our customers’ expectations of pricing, quality and on-time delivery. To achieve our mission, JasonMould:

  • Commits to continually improve employee skills and efficiency,
  • Provides our employees a clean and safe working environment,
  • Upgrades machine technology and support equipment through a strict maintenance program, and
  • Maintains customers’ tooling to its highest peak of performance

For more about China injection molding cost,please visit https://www.jasonmolding.com/

Inquiry Contact:

Contact person: James Yuan

Company name: JasonMould Industrial Company Limited

Address: LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China

Telephone: 86-752-6682869

Email: info@jasonmolding.com

Website: https://www.jasonmolding.com

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