Engineering topics

Fang, Zhigang Zak

Publications and source records attributed to Fang, Zhigang Zak.

4 records

DOE OSTI2021

Methods and systems for 3D printing with powders

A method of printing a three dimensional article (201) can include forming a bottom layer of the three dimensional article (201) by spraying a dry build material powder (210) onto a build platform (230) while heating the dry build material powder (210). The dry build material powder (210) can include metal or ceramic particles mixed with a polymeric binder having a softening point temperature. The dry build material powder (210) can be heated to a temperature above the softening point temperature such that the dry build material powder (210) adheres to the build platform (230). Subsequent layers can be formed by spraying dry build material powder (210) onto a lower layer while heating the dry build material powder (210) such that the dry build material powder (210) adheres to the lower layer.

Fang, Zhigang Zak↗

DOE OSTI2021

Methods of producing a titanium alloy product

A method for producing a particulate titanium alloy product can include preparing a composite particulate oxide mixture with TiO2 powder and at least one alloying element powder. The composite particulate oxide mixture can be co-reduced using a metallic reducing agent under a hydrogen atmosphere at a reduction temperature for a reduction time sufficient to produce a hydrogenated titanium alloy product. The hydrogenated titanium alloy product can then be heat treated under a hydrogen atmosphere and a heat treating temperature to reduce pore size and specific surface area to form a heat treated hydrogenated titanium product. The heat treated hydrogenated titanium product can be deoxygenated to reduce residual oxygen to less than 0.2 wt % to form a deoxygenated hydrogenated titanium product as a particulate. The deoxygenated hydrogenated titanium product can optionally be dehydrogenated to form the titanium alloy product as a particulate.

Fang, Zhigang Zak↗

DOE OSTI2020

Methods of producing a titanium product

A method (500) for producing a titanium product is disclosed. The method (500) can include obtaining TiO2-slag (501) and reducing impurities in the TiO2-slag (502) to form purified TiO2 (503). The method (500) can also include reducing the purified TiO2 using a metallic reducing agent (504) to form a hydrogenated titanium product comprising TiH2 (505). The hydrogenated titanium product can be dehydrogenated (506) to form a titanium product (508). The titanium product can also be optionally deoxygenated (507) to reduce oxygen content.

36 MATERIALS SCIENCE↗

DOE OSTI2020

The effect of Ni doping on the mechanical behavior of tungsten

The effect of nickel (Ni) on activated sintering of tungsten has been known and investigated for decades. However, there are few reports on the mechanical properties of tungsten when Ni is added as a low alloying additive with less than 1 wt%. In this work, the mechanical behaviors of tungsten doped with 0.2–1.0 wt% nickel from room temperature up to 400 °C were investigated. The results show that the compression ductility of as-sintered Ni doped tungsten is drastically higher than that of as-sintered pure tungsten at all tested temperatures including room temperature, and the fracture toughness at room temperature is increased by 92%. The results suggest that the ductile-to-brittle transition temperature (DBTT) of tungsten can be reduced substantially by doping with Ni.

36 MATERIALS SCIENCE↗