SE439064B - PROCEDURE FOR PREPARING AN ARM BREAKING PROJECT - Google Patents

Description

27311973-2 of at least 4200 N / mmz and in connection therewith in rod form is pressed through a nozzle, whereby the spherical tungsten grains are transformed into elongated grains.

The process according to the invention is described in the following with reference to the accompanying drawings, in which - Fig. 1 is a structural image of sintered tungsten-heavy metal at 100 times magnification, Fig. 2 is a structural image of the same tungsten-heavy metal as in Fig. 1 with longitudinally deformed tungsten grains, and Fig. 3 is a structural view of the tungsten heavy metal shown in Fig. 1 with more longitudinally deformed tungsten grains.

"This tungsten heavy metal after pressing and sintering has the following properties: Breaking stress CYB = 90 kp / mmz Tin elongation f 5 = 15% specific gravity X = 17 g / cm3 Hardness HV = 300 kp / mmz 10 This heavy metal1 sintering alloy is formed further after pressing and sintering.The rod material can, for example, be pressed through a nozzle, whereby the cross section of the rod material is reduced.

According to Fig. 2, the cross section is reduced by 25% and according to Fig. 3, the cross section is reduced by 40%. The hardness is then increased to Hvlo = 420 kp / mmz and HV10 = 500 kp / mmz.

By deformation of the heavy metal sintered alloy for densification is meant only the molding after pressing and sintering.

By chipless deformation is meant not only the above-mentioned pressing of a rod through a nozzle, but also stretching, upsetting, rolling, forging, hammering, etc. and thus also any shaping which leads to a densification of the workpiece.

This can be both cold and hot forming, in which plastic deformation of the workpiece takes place.

In some cases, only part of the projectile body is densified. The deformation can also be called "deformation" and "reshaping".

Reshaping: "Changing the shape of a workpiece by displacing its constituents while maintaining their bonds. recrystallization temperature ("hot" and "cold").

Thermoforming generally allows for a higher degree of transformation at smaller forces; disadvantageous are the costs of heating, the greater inaccuracy due to wastage and scaling. Cold forming provides greater accuracy on larger surfaces, but requires higher forces and allows only a smaller degree of transformation. In addition, considerable densification occurs to an undesirable degree, which must be eliminated by intermediate fertilization. ”Deformation:“ Metallografiz plastic deformation.

The deformability in the solid state is due to the fact that the crystallinity of metals is prone to slipping and twin formation according to certain laws and can thus be deformed by rolling, forging, pressing, drawing b1.a. During thermoforming, new crystals, recrystallization, are formed in the formed structure. In this way, cast blocks with large cross-sections can be transformed into the finest plates and wires. In cold forming, density, yield strength and hardness increase, while tensile strength decreases just before fracture. "

Claims (1)

A process for producing from heavy metal powder an armor-piercing projectile having a projectile body for combating single and multiple targets from a tungsten containing heavy metal 1 sintering alloy, wherein the pressed and sintered alloy powder by a cross-sectional reduction of at least 20% with a hardness Hvlo of at least 4200 N / mmz and subsequently in rod form is pressed through a nozzle, whereby the spherical tungsten grains are transformed into elongated grains.