KOVAR ALLOY Rod Heat Treatment Method

Introduction to KOVAR(4J29) Precision Alloy

KOVAR(4J29) Precision Alloy, commonly known as Kovar, is an iron-nickel-cobalt alloy. It is widely used in electronic tubes, integrated circuits, optoelectronic devices and lasers for its low thermal expansion coefficient and excellent mechanical properties. Its composition ratio is usually 29% nickel, 17% cobalt, and the rest is iron and trace elements. The heat treatment process and yield of KOVAR(4J29) precision alloy directly affect its performance and application effect.

Heat treatment process of KOVAR(4J29) precision alloy

The heat treatment process of KOVAR(4J29) precision alloy mainly includes solution treatment, aging treatment and recrystallization annealing. Each step of the process has an important influence on the final performance of the material.

Solution treatment

Solution treatment is to form a uniform solid solution of the elements in the alloy by high temperature heating to eliminate internal stress and improve toughness. The solution treatment of KOVAR(4J29) alloy is usually carried out between 980℃ and 1000℃, with a holding time of 1 to 2 hours, and then rapidly cooled.

Temperature: 980℃ to 1000℃

Hot-holding time: 1 to 2 hours

Cooling method: Rapid cooling (usually water cooling)

Aging treatment

Aging treatment aims to redistribute the precipitated phase in the alloy by medium-temperature heating to enhance the mechanical properties and stability of the material. The aging treatment temperature of KOVAR(4J29) alloy is usually 450℃ to 500℃, the holding time is 3 to 5 hours, and then cooled with the furnace.

Temperature: 450℃ to 500℃

Hot-holding time: 3 to 5 hours

Cooling method: Furnace cooling

Recrystallization annealing

Recrystallization annealing is used to eliminate work hardening and restore the plasticity of the material. For KOVAR(4J29) alloy, the recrystallization annealing temperature is generally 700℃ to 750℃, the holding time is 1 hour, and then gradually cooled to room temperature.

Temperature: 700℃ to 750℃

Hot-keeping time: 1 hour

Cooling method: gradual cooling