Warhead Fragmentation Jacket Fixture Positioning
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Solution Overview
Problem
Current methods for producing fragmentation jackets for explosives-charged warheads using powder metallurgy face challenges such as pressure leakage, porosity, and high frequency of shrinkage cracks, particularly when embedding a large quantity of heavy metal balls, which affects the uniformity and effectiveness of fragment dispersion.
Innovation Solution
A method involving a fixture to define the location of heavy metal balls within a powder metal casing, allowing them to be embedded completely free from contact, followed by compacting and sintering to prevent shrinkage cracks, and subsequent machining to achieve a homogenous metal part with predetermined fragment distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heavy metal balls are embedded in powder metal using conventional methods, then fragmentation jacket can be produced, but shrinkage cracks occur during sintering
Solution Approach 1:
The heavy metal balls are positioned in a fixture before the powder metal is added and compacted. This preliminary positioning ensures that the balls are correctly located before sintering, preventing shrinkage cracks and ensuring uniform distribution throughout the fragmentation jacket.
Solution Approach 2:
A fixture is used as an intermediary tool to hold and position the heavy metal balls in the correct locations before the powder metal is compacted around them. The fixture acts as a mediator that ensures proper spacing and positioning, which is maintained through the sintering process.
2Force
If heavy metal balls are tightly packed in fragmentation jacket, then penetration capability is improved, but pressure leakage occurs during detonation
Solution Approach 1:
The heavy metal balls are distributed with specific spacing throughout the fragmentation jacket rather than being tightly packed. This local quality approach ensures that there is adequate space around each ball for proper detonation and fragment ejection, while still maintaining sufficient density for penetration capability.
3Manufacturing precision
If powder metal is compacted at high pressure to embed heavy metal balls, then embedding uniformity is improved, but porosity increases
Solution Approach 1:
The heavy metal balls are positioned in a fixture before powder metal compaction. This preliminary positioning allows for controlled compaction that achieves uniform embedding without excessive pressure that would cause porosity. The fixture ensures proper spacing is maintained during the compaction process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the production of fragmentation jackets with varied fragment dimensions and sizes within different sections, ensuring effective penetration and dispersion without cracks, enhancing the performance of explosives-charged warheads.
Implementation Method 1
the powder material is first cold isostatic compressed until the desired density is achieved, after which the compressed powder granules are sintered in a separate process until a homogenous metal is formed
Implementation Method 2
The said heavy metal balls that are projected at high velocity by the detonation of the explosive generate good penetration even in semi-hard targets
Data Source
AI summary
The present invention is directed to a method for production preformed fabrication casing or associated parts intended to generate fragments initiated by the explosive of contained warhead charges. Molded parts having fragmentation bodies (4, 21, 34) embedded therein are produced by a two-stage powder compaction method followed by sintering together the compacted powder metal. The method described in the present invention defines how in an initial stage the fragmentation bodies (4, 21, 34) are fixed in position using a fixture (2) after which the bodies are covered with powder metal that is then compacted until the powder forms a single molded part (2) after which the fixture is replaced with a secondary quantity of powder that is also compacted to form a self-supporting unit (12) together with the first quantity of powder.