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DFT® wire

DFT® composites were developed to combine the desired physical and mechanical attributes of two or more materials into a single wire or ribbon system. As a result of extreme compressive forces imparted during the processing of the dissimilar materials, the mechanical bond formed between surfaces has been found to be metallurgically sound. This feature has given rise to a number of novel applications of DFT® wire, cable or ribbon.

One of the more common uses of DFT® wire is found in the medical device industry where designers have integrated the strength and biocompatibility of implant grade alloys with desired properties of other materials. The composite typically uses the outer sheath to impart strength while the core material is designed to provide conductivity, radiopacity, resiliency or MRI enhancement.

DFT® wire enables the unique ability to match dissimilar materials to provide a variety of properties in a single wire system. This technology can be utilized by the engineer to resolve technical issues cost effectively.


Size

Fort Wayne Metals has the capability to create these DFT® wire materials in sizes from 3.175 mm to 0.017 mm [0.125 in to 0.0007 in] or smaller depending on the constituents.


Values and Compositions

A typical 35N LT®/Silver DFT®wire material (MP-DFT-Ag) may have a variety of tensile values depending upon the amount of cold work and core percentages of the individual wires. In addition, the table in Fig. 2 is presented to compare the electrical resistivity of various core percentages to that of solid 35N LT® wire, a common pacemaker lead material. 35N LT®, 316LVM and Conichrome® tubing is kept in stock for the outer sheath. Core options, in wire form, are more abundant in general inventory.


Typical Tensile Values for MP-DFT Wire with a Silver Core (PSI)

Since DFT® composites are highly customizable, exact mechanical properties vary based on construction, primarily influenced by coldwork percentages and fill ratio. You can use the chart below to compare properties for 35N LT® alloy DFT® composites with a variety of coldwork percentages and silver fill ratios.

% CW 25% Ag 28% Ag 33% Ag 41% Ag
0% 158,200 148,800 149,600 124,100
20% 201,300 191,200 192,600 162,800
37% 225,600 216,500 213,800 165,800
50% 237,300 227,300 224,700 192,400
61% 246,000 236,000 232,400 200,000
69% 256,700 244,000 239,300 206,400
75% 261,200 248,100 242,300 209,500
80% 267,800 254,500 249,300 214,900
84% 276,000 264,000 261,600 217,000
87% 278,200 264,300 262,300 225,000
90% 277,300 264,300 258,400 223,300
92% 281,900 266,900 254,700 232,200

Typical electrical resistance

Since DFT® composites are commonly used as conductors, you can use the table below to compare 35N LT® alloy DFT® composites with a silver core to solid 35N LT® alloy wire.

Size 25% Ag 28% Ag 33% Ag 41% Ag Solid 35N LT® Wire
0.006 1.0132 0.9104 0.7788 0.6324 17.26
0.004 2.2797 2.0489 1.7521 1.4228 38.84
0.002 9.1126 8.1911 7.0064 5.6914 155.34
0.001 36.5347 32.7598 28.7598 22.7663 621.38

Core Material

Tubing Materials