Common Defects and Solutions in Titanium Wire Preparation

 Nowadays, titanium materials have taken an irreplaceable position in various industries, so the manufacturers need to strictly control its production quality. However, due to the influence of multiple factors such as material properties, process parameters, and equipment status, it is very easy to have these defects during the production. They will directly affect product quality and performance. Thus, we have summarized the 7 most common defects in titanium wire production for your reference, in order to improve the product qualification rate.

 

 

During the preparation of titanium wires, uneven scratches or friction marks of varying depths may appear on the surface, which is the most common surface defect.

Causes: During the drawing or processing, due to incomplete surface treatment, insufficient lubrication, impurities mixed into the lubricant, sand adhering to the metal surface, or defects on the tool surface, friction with the titanium wire causes damage.

Solutions:

1. Strictly follow the operating procedures for surface treatment to ensure thorough and uniform treatment;

2. Select appropriate lubricants to ensure uniform coverage of the titanium wire surface and sufficient lubrication;

3. Regularly filter the lubricants to avoid impurities such as sand from being mixed in;

4. Regularly inspect and repair tools to ensure smoothness and no flaws on the tool surface.

The key defects that need to be strictly controlled during the preparation process, such as the diameter of the titanium wire, do not meeting the technical requirements, will directly affect the subsequent assembly and usage effects.

Causes: The mold size is disqualification, which will directly lead to the deviation of the titanium wire diameter; excessive corrosion or uneven local corrosion during the acid washing process will damage the dimensional accuracy.

Solutions：

1. Carefully check the mold size before stretching to ensure it meets the technical standards;

2. Continuously turn the titanium wire during acid washing to ensure uniform corrosion on all parts;

3. Monitor the diameter of the wire in real time and adjust the acid washing parameters according to the actual situation to prevent excessive corrosion.

In the annealing or rewinding process, titanium wire surface oxide spots or oxide layer occur frequently, which not only affect the cleanliness of the appearance but also reduce the core corrosion resistance of the wire.

Causes: The insufficient vacuum degree of the annealing furnace causes the titanium wire contacting with oxygen; the too high unloading temperature accelerates the oxidation reaction; during rewinding, the surface of the titanium wire is polluted, leading to local oxidation.

Solutions:

1. Ensure that the vacuum degree of the annealing furnace meets the process requirements, reducing the contact with oxygen;

2. Strictly control the unloading temperature under 200℃;

3. Clean the surface of the titanium wire before rewinding to avoid oil, dust, etc.

Internal cracks occur within the titanium wire, which are difficult to detect with the naked eye, but they significantly reduce the mechanical properties and, in severe cases, may cause sudden fracture during use, posing extremely high risks.

Causes:

1. The titanium alloy raw materials contain refractory metal elements, causing metallurgical defects;

2. Rapid cooling during drawing and uneven temperature distribution lead to concentrated internal stress.

Solutions:

1. Strengthen the control of material composition to ensure that the content of each element meets the standards;

2. Use the preheating and insulation measures to avoid fast cooling;

3. Monitor the real-time temperature during drawing, ensuring even temperature of the titanium wire.

At the edges of the raw material, cracks will extend along the length of the titanium wire. As a result, it will directly damage the continuity of the titanium wire structure and affect its stability in use.

Causes:; when cooling the high-temperature titanium alloy by water, the cooling speed at the edges of the billet is too fast, causing the cracking.

Solutions:

1. Precisely control the chamfering temperature to avoid rapid cooling at the edges;

2. Use a slow cooling process when the high-temperature titanium alloy is water-cooled to disperse the stress;

3. Strict quality inspection and promptly remove cracked titanium wires to prevent them from entering the next process.

Due to defects in the raw materials, point-like protrusions or depressions appear on the surface of the titanium wire. If not dealt with promptly, these defects may expand into larger ones during subsequent processing.

Causes: Metallurgical defects such as holes and compositional segregation exist at the end face of the pure titanium rods. During the drawing process, these defects are retained and may expand.

Solutions:

1. Optimize the melting process, increase the melting temperature and time to promote uniformity of composition;

2. Strengthen the detection of raw material composition, strictly control uniformity to avoid local defects;

3. Screen the raw materials of titanium rods and remove the billets with point-like defects.

Hydrogen-induced cracks means the cracks that appear after welding or processing. This problem significantly reduces the toughness and strength of titanium wires, and seriously affects the products' service life.

Causes: When the surface of the base material or the welding wire is contaminated, or when the humidity of the environment is too high, the hydrogen content during the welding or processing process will exceed the standard.

Solutions:

1. Using mechanical or chemical methods to remove impurities such as oil, oxides on the base material, and welding wire surfaces before welding.

2. Control the humidity of the working environment, avoid welding or processing in a humid environment.

3. Choose high-purity protective gas to reduce the mixture of hydrogen.

Every step in the production of titanium wire is crucial to the quality of the product. Only by strictly controlling the quality at each step can we effectively reduce the defects and enhance the stability of the product.