Die life is related to die type and structure, it is a certain period of die material performance, die design and manufacturing level.The comprehensive reflection of die heat treatment level and use and maintenance level.To a certain extent, die life reflects the level of metallurgical industry and machinery manufacturing industry in a region and a country.

There are three kinds of scrapping forms, namely abrasion, breakage  and plastic deformation.

(1) abrasion scrapping

When the die is in working, it touched with the aluminum billet and produces relative movement.The gradual loss of material from the contact surface due to the relative motion of the surface is called abrasion.

(2) breakage  scrapping

breakage  scrapping occurs when the die is cracked or separated into two parts or several parts lose service ability.breakage  can be divided into plastic breakage  and brittle breakage .The die material is mostly medium and high strength steel, and the form of breakage  is brittle breakage .

Brittle breakage  can be divided into one-time breakage  and fatigue breakage .

(3) Deformation scrapping

die deformation is the extrusion process of die metal material.The mechanical load and the room temperature strength of the die play a leading role in whether deformation occurs.In high temperature service, whether the die deformation, mainly depends on the working temperature of the die and die material high temperature strength.