Experimental Study of Forming Rene95 Alloy Parts by Laser Cladding

 In this paper, experimental study of forming metal parts by laser cladding Rene95 alloy powder was reported. The influence of main process parameters, such as laser power, scanning speed and laser beam diameter, on the thickness, width and the angle of the laser cladding track was investigated. The microstructures of laser cladding parts were studied and compared with those of common casting parts. The obtained Rene95 metal parts formed by laser cladding are dense and of high strength.
Near Net Shape production of metal components using LENS
Rapid Prototyping and Near Net Shape manufacturing technologies are the subject of considerable attention and development efforts. At Sandia National Laboratories, one such effort is LENS (Laser Engineered Net Shaping). The LENS process utilizes a stream of powder and a focused Nd YAG laser to build near net shape fully dense metal parts. In this process, a 3-D solid model is sliced, then an X-Y table is rastered under the beam to build each slice. The laser 1 powder head is incremented upward with each slice and the deposition process is controlled via shuttering of the laser. At present, this process is capable of producing fully dense metal parts of iron, nickel and titanium alloys including tool steels and aluminides. Tungsten components have also been produced. A unique aspect of this process is the ability to produce components wherein the composition varies at differing locations in the part. Such compositional variations may be accomplished in either a stepped or graded fashion. In this paper, the details of the process will be described. The deposition mechanism will be characterized and microstructures and their associated properties will be discussed. Examples of parts which have been produced will be shown and issues regarding dimensional control and surface finish will be addressed.
Laser forming near shapes in titanium
A new collaborative program sponsored by the DoD Advanced Research Projects Agency (ARPA) and the Office of Naval Research (ONR) has been initiated. The program’s goals are to develop and demonstrate a laser based, rapid prototyping system for titanium and its alloys. Titanium (and alloy) near shapes have been formed from economical precursor metal powders such as raw, sieved titanium Kroll fines and titanium fines blended with elemental alloying powders. In preliminary tests, the sequential laser fusion of thin, laminar metal-powder layers to form integral, 100 percent dense structures has been demonstrated. A 14 Kw CO2 CW high-energy laser was used to form titanium bars and a 4-inch diameter (1-inch wall) cylinder. The laser forming operation was performed in a special argon swept atmosphere control chamber that remained below 30 ppm oxygen during operations. Materials characterization tests showed excellent chemistry control, and mechanical properties exceeding American Society for Testing Materials (ASTM) specifications for C-2 titanium. Economic projections for titanium parts formed in a dedicated laser forming system using the operational parameters developed show cost advantages over cast and forged structures. The process appears advantageous for hard to cast, forge, or form metals such as titanium, niobium, composites, and others; both in time to delivery and final article cost. The process appears well suited for the laser forming of large, near-shape structures directly from metal powders and elemental alloy mixtures without using molds or dies, by the direct download and postprocessing of electronic part descriptions. Further work is planned.A new collaborative program sponsored by the DoD Advanced Research Projects Agency (ARPA) and the Office of Naval Research (ONR) has been initiated. The program’s goals are to develop and demonstrate a laser based, rapid prototyping system for titanium and its alloys. Titanium (and alloy) near shapes have been formed from economical precursor metal powders such as raw, sieved titanium Kroll fines and titanium fines blended with elemental alloying powders. In preliminary tests, the sequential laser fusion of thin, laminar metal-powder layers to form integral, 100 percent dense structures has been demonstrated. A 14 Kw CO2 CW high-energy laser was used to form titanium bars and a 4-inch diameter (1-inch wall) cylinder. The laser forming operation was performed in a special argon swept atmosphere control chamber that remained below 30 ppm oxygen during operations. Materials characterization tests showed excellent chemistry control, and mechanical properties exceeding American Society for Testing Materials (A...