WO1998055257A1

WO1998055257A1 - Production of elongated articles from particulates

Info

Publication number: WO1998055257A1
Application number: PCT/US1998/001360
Authority: WO
Inventors: Raymond D. Dixon; Gary K. Lewis; John O. Milewski
Original assignee: The Regents Of The University Of California
Priority date: 1997-01-24
Filing date: 1998-01-22
Publication date: 1998-12-10
Also published as: AU6317098A

Abstract

A method and apparatus for forming an elongated article, such as a wire or rod, by an additive directed light fabrication process is disclosed. The elongated article (50) is formed by melting and depositing particulate material into a deposition zone (28) which has been designed to yield the desired article shape and dimensions. The article is withdrawn form the deposition zone as it is formed, thus enabling formation of the article in a continuous process. Alternatively, the deposition zone is moved along any of numerous deposition paths away from the article being formed.

Description

PRODUCTION OF ELONGATED ARTICLES FROM PARTICULATES

TECHNICAL FIELD

This invention relates to the fabrication of articles from particulate matter. This

invention relates more particularly to the fabrication of wire or rod from particulate

matter.

This invention was made with government support under Contract No. W-7405-

ENG-36 awarded by the U.S. Department of Energy. The government has certain

rights in the invention.

BACKGROUND ART

Rods and wire have been made by melting the metal or alloy from which the

wire or rod is to be formed, casting an ingot from the molten metal or alloy,

processing the ingot in a rolling mill, and drawing the rolled metal or alloy through a

forming die into the desired rod or wire diameter. Extrusion processes for making

wire are also available.

These methods generally require use of heavy equipment and tools, heat

treatments for casting, forging, drawing, or extruding or both, and annealing. The

traditional methods also generally require many iterative sequences of steps to achieve

the final diameters of wire or rod.

The types of material from which the rod or wire can be made by traditional

multi-step processes are also limited to metals or alloys which can be plastically deformed and extruded and economically processed by these methods. Brittle, low

ductility materials do not easily lend themselves to deformation processing.

Expensive wire drawing dies are subject to abrasion in using traditional

manufacturing methods to make wire of hard or abrasive materials.

Conventional processing of metals or alloys into wires or rods can result in

contamination which can significantly affect the mechanical or metallurgical

properties of the finished wires or rods.

There have been developed methods of making articles using metal powder

melted by a laser beam, as disclosed in U.S. Patent No. 4,724,299. U.S. Patent No.

5 , 111 ,021 discloses addition of material to a surface using a laser beam and metal

powder. Although these patents disclose cladding or encrusting existing surfaces on

articles, they do not disclose formation of defined wires or rods.

U.S. Patent No. 4,743,733 discloses repair of an article by directing a laser

beam and a stream of metal powder to a region of the article which needs repair.

These repair methods rely on support of the molten pool by a previously existing

substrate of the article being repaired.

U.S. Patent No. 4,323,756 discloses a method for producing metallic articles

from metal powders and substrates which become part of the articles. A focused

energy beam is used to create a molten pool on a substrate and metal powder is

supplied to a point outside of the area at which the beam impinges upon the substrate.

Movement of the substrate then carries the powder into the beam and molten pool,

where it melts and mixes with the melted substrate material. There is still a need for methods of making wire and rod which do not require

extreme operating conditions, heavy equipment and large capital outlays. There is

also a need for methods of making wire and rod in fewer processing steps. Methods

and apparatuses are needed for making wire and rod from more different types of

materials than can easily be processes in the traditional manufacturing methods and

apparatuses. There is also a need for ways of reducing or eliminating contaminants in

wire or rod products.

It is an object of this invention to provide a single-step method of making wire

and rod.

It is another object of this invention to provide a method of making wire and

rod from a larger variety of materials than the metals and alloys from which wire and

rod are now made.

It is a further object of this invention to provide a method of making wire and

rod from a broad selection of particulate materials.

It is still another object of this invention to provide a method of making wire

and rod which reduces or eliminates contamination of the wire and rod articles.

It is yet another object of this invention to provide a laser deposition process

for making wire and rod.

It is a still further object of this invention to provide a method of making wire

and rod with specific properties such as microstructural or magnetic orientation.

Additional objects, advantages and novel features of the invention will be set

forth in part in the description which follows, and in part will become apparent to

those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized

and attained by means of the instrumentalities and combinations particularly pointed

out in the appended claims.

DISCLOSURE OF INVENTION

To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, there has been invented a method of making elongated articles from materials in particulate form comprising: (a) defining the shape and dimensions of an article; (b) providing a means for introducing particulate material into a deposition zone;

(c) creating a deposition path and control commands effective to form the article by deposition of molten material;

(d) focusing a laser beam at a location within the deposition zone;

(e) providing particulate material to the deposition zone; (f) forming a pool of molten material in the deposition zone by melting a portion of an article support and the particulate material by means of energy provided by the laser beam;

(g) depositing molten material from the deposition zone on the article support at points along a first portion of the deposition path by moving the deposition zone along the deposition path, where the molten material solidifies after leaving the deposition zone, in order to form a portion of the article which is adjacent to the article support;

(h) forming a pool of molten material in the deposition zone by melting a portion of the partially formed portion of article and the particulate material by means of energy provided by the laser beam;

(i) depositing molten material from the deposition zone at points along a second portion of the deposition path by moving the deposition zone along the deposition path, where the molten material solidifies after leaving the deposition zone, in order to continue formation of the article; and (j) controlling flow of particulate material into the deposition zone, energy density of the laser beam and focal position of laser beam by means of the control commands as deposition takes place.

Alternatively, instead of moving the deposition zone along a deposition path, as in steps (g) and (i), the deposition zone can be focused and held in constant position with the wire or rod being withdrawn from the deposition zone as it is formed. Provisions can be made for recycling any unused particulate material in the process.

In another embodiment, an apparatus for carrying out the process of this invention is provided. The inventive apparatus comprises: (a) a means for defining the shape and dimensions of an article, this means being capable of creating a deposition path and control commands effective to form an article by depositions of molten material;

(b) a means for introducing particulate material into a deposition zone;

(c) a laser positioned to focus a laser beam into the particulate material in the deposition zone;

(d) a means for supporting and drawing the article away from the deposition zone;

(e) a means for controlling flow of the particulate material, energy density of the laser beam, focal position of laser beam, and speed of withdrawal of the article being formed from the deposition zone by using the control commands. Alternatively, instead of having a means to withdraw the article from the

deposition zone, there is provided a means for moving the deposition zone along the

deposition path away from the article being formed. Provisions can be made for

recycling any unused particulate material in the process.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of the

specification, illustrate some of the embodiments of the present invention and,

together with the description, serve to explain the principles of the invention. In the

drawings:

Figure 1 is a schematic representation of rod formation in accordance with the

present invention wherein free standing rods of any diameter can be formed by any

combination of x, y, z or rotary motion.

Figure 2 is a schematic representation of continuous processing of material

and wire formation in accordance with the present invention.

Figure 3 is a schematic representation of a set up for making wire or rod from

a three-component particle mixture.

Figures 4a, 4b, 4c and 4d show examples of some of the various deposition

paths which can be used in the practice of the present invention to create the relative

motion needed to form the cross sections of wire, rod or bar shapes.

Figure 5 shows a metallographic cross section of a nickel based alloy rod

made using a layered deposition path.

Figures 6a and 6b show a metallographic cross section and longitudinal

section of a fully dense titanium aluminum alloy rod made in accordance with the

present invention.

Figure 7 shows thin wire segments made from 316 stainless steel, tungsten,

nickel aluminide and molybdenum disilicide in accordance with the present invention.

Figure 8a is a flow chart of conventional wire manufacture compared with a

flow chart (Figure 8b) of the invention method of wire manufacture. Figures 9a, 9b and 9c show the powder used, microstructure as shown in a

micrograph of a polished cross section and fracture surface, respectively, of wire made

in accordance with the invention from 316 stainless steel.

Figures 10a, 10b and 10c show the powder used, microstructure as shown in a

micrograph of a polished cross section, and fracture surface, respectively, of wire

made in accordance with the invention from tungsten.

Figures 11a, l ib and l ie show the powder used, microstructure as shown in a

made in accordance with the invention from nickel aluminide.

Figures 12a, 12b and 12c show the powder used, microstructure as shown in a

made in accordance with the invention from molybdenum disicilide.

BEST MODES FOR CARRYING OUT THE INVENTION

It has been discovered that articles, particularly elongated articles in the form

of wires or rods, can be produced by an additive directed light fabrication process.

An elongated article such as a wire or rod is constructed by melting and

depositing particulate material into a deposition zone which has been designed to

yield the desired article shape and dimensions. The article is withdrawn from the

deposition zone as it is formed, thus enabling formation of the article in a continuous

process. The process of this invention can be carried out using laser light as the means

for melting the particulate material. Suitable pulsed or continuous wave lasers include

those which produce sufficient energy to melt the materials from which it is desired to

form wire or rod. Suitable optics to achieve focus and energy densities to concentrate

the energy required for melting of the selected materials are needed.

The directionality of the laser beam with respect to the deposit is guided by

computerized numerical control (CNC) machine commands or electromechanical

means to directly deposit particulate metal to form an accurately configured, fully

dense metal article. No molds, patterns or masks are required, only the precise

articulation of the laser and stream of particulate material in relation to the deposit to

form the article. The articulation of a three-dimensional relative motion controls and

configures the material deposition and resultant geometry of the articles being formed.

Once begun, the invention method can continuously process material without

stopping, including the sectioning and packaging of the product.

An article support or substrate, generally a stub of wire or rod or other article

having compatible geometry, made of a metallurgically compatible material, is

mounted in a means for withdrawing the elongated formed article from the deposition

zone. The article support is positioned so that the laser light strikes a trailing end of

the article support as the first of the particulate material is deposited upon the trailing

end of the article support as it melts.

The substrate or article support upon which the particulate material is

deposited may be crystallographically oriented such as when a single crystal is used

for the article support. When a single oriented crystal is used as a support for the invention method of making wire or rod, in combination with the unidirectional heat

flow produced by the process and epitaxial grain growth of a preferred orientation in

the wire or rod being produced can be accomplished. This embodiment of the

invention can be used to make a solidified (fully dense) wire or rod product with

unique metallographic properties.

Elongated articles having specific magnetic orientations can also be made

using the invention method. To do this the substrate or article support upon which the

particulate material is deposited is magnetically oriented such as when a magnet is

used for the article support. When a magnetic material is used as a support for the

invention method of making wire or rod, epitaxial grain growth of a preferred

magnetic orientation in the wire or rod being produced can be accomplished.

Alternatively, the deposition zone can be exposed to a magnetic field produced

independently of the article support. Exposure of the deposition zone to a magnetic

field having a selected orientation can be used to produce epitaxial grain growth with

desired magnetic orientations.

To start fabrication of an article, a small portion of the article support is melted

by the laser beam to form a molten pool. If the molten zone is too large or too small,

the stability and integrity of the process decreases. Therefore, the processing

variables (such as powder flow, delivery gas flow, laser power, laser focus, and

relative motion must be precisely controlled and are very important in producing rods

or wires having uniform dimensions and composition.

At least one stream of solid particulate material, or powder, is supplied to the

point where the laser light is focused. This generally done by means of gravity, mechanical feed mechanism, an assist gas with an eductor, or a combination of any of

these feed mechanisms. A key feature of the powder delivery mechanism is that

rather than merely delivering particulate material to the focal zone of the laser, the

powder delivery mechanism can deliver at least one focused stream of particulate

material co-focally to the laser energy.

The particulate material is melted by heat generated when the laser light

strikes the particles and by transfer of heat from the molten pool to the particulate

material as the particulate material comes into contact with the molten pool.

After a small amount of material has been melted, the molten pool volume

increases and begins to be enlarged by the introduction of more particulate material

and laser energy. A continuous solid microstructure is achieved by maintaining a

continuous solidification front when using a continuous wave laser or by remelting a

portion of the previously deposited material and solidification when using a pulsed

laser.

The space containing and surrounding the molten pool, the laser focal spot

size, the "focal point" of the stream of particulate material, the focal point location of

the laser beam, and that portion of the laser beam where energy density is great

enough to melt the particulate material is termed the deposition zone.

As molten particulate material is deposited and cooled, a portion of the cooled,

solidified particulate material can be re-melted by the impinging laser light and is

mingled with the molten particulate material being newly formed. The method of this

invention relies in part on precise focus of the stream of particulate material directly

into the laser beam and molten pool which provides for both preheating of the particulate material by the beam and melting of the particulate material by entry of the

particulate material into the molten pool. Uniform deposition can best be achieved by

having the laser energy and powder in co-focal positions.

The deposition rates can be precisely controlled to achieve cooling rates

ranging from 10 K/sec to more than 10⁵ K/sec. This broad range of deposition rates

enables a wide range of deposit geometry and microstructures.

The motion command sequence of control moves the focal zone of the laser

systematically relative to the length of the wire or rod to fuse metal powder particles

that are delivered to the focal zone into solid metal and form the wire or rod

continuously.

Alternatively, the laser and powder deposition devices can be held in constant

position while the formed wire or rod is withdrawn from the deposition zone as

deposits consisting of the particulate material are consolidated by melting and

subsequently solidified due to loss of heat to the surroundings.

The focal point of the laser light can be moved about a path in accordance with

computerized numerical control software. As an example, the focal point of the laser

can be programmed to move along a helical path to produce a coil or spring geometry

for continuous indefinite lengths or to increase the diameter of a rod.

However, the processes of this invention do not rely exclusively on a three-

dimensional solid computer based model. The method of this invention also provides

for the fabrication of wire or rod with a high directionally oriented microstructure due

to the potential for microstructural growth under near unidirection heat flow and

solidification conditions. The invention method can be used to make discrete, single articles one at a

time. Alternatively, the invention method can be used for producing continuous

uninterrupted runs. For example, as deposited wire is formed continuously, it can be

taken up onto spools positioned outside the processing chamber, without stopping or

even slowing production between spools.

With reference to Figure 1, in one embodiment of the invention, a beam from

an Nd: YAG laser __0 is delivered by means of a fiber optic 12 through a laser window

14, into a containment chamber j_8, to a sealed boot 20 that holds a laser focusing

head 22.

The means for withdrawing the focusing head 22 from the formed wire or rod

and the articulation and relative x, y, z, or rotary motion of the deposition zone 28 can

also be contained within the sealed containment chamber j_8. Alternatively, the means

for withdrawing the wire or rod from a deposition zone can be outside the sealed

chamber.

The focused laser beam 24 enters the containment chamber 18 through a

quartz laser window _____ in a nozzle .16 that also delivers the particulate material to the

focal zone 30.

For many applications, the entire process takes place in an inert gas

atmosphere in the sealed containment chamber ]_8 if that is made desirable by the

properties of the material being processed. The sealed chamber atmosphere can be

conditioned by a dry train 64 that reduces the oxygen content within the chamber to

5ppm or less. Employment of a sealed chamber to control the atmosphere is useful

when processing materials which would be reactive with oxygen or moisture in the air or when oxygen or moisture could become unintentionally incorporated into the

product. Relatively unreactive gases such as nitrogen or argon can be used. However,

when processing less reactive materials such as precious metals or some steels, the

invention can be practiced without use of a sealed chamber.

In the upper right of the schematic of Figure 1 is a powder mixing chamber 38.

The powder mixing chamber 38 can be evacuated and backfilled with inert gas. The

powder feeder 32 entrains the particulate material in an inert gas stream that delivers

the particulate material to the laser focus nozzle 16 and then to the focal zone 30.

Optionally a powder stream splitter 78 can be used to direct a plurality of powder

streams into the deposition zone from a plurality of directions. The inert gas stream

can be recycled from the containment chamber J_8 back into the delivery gas supply

40 or back into the delivery gas supply 40 by way of a gas purifier, treatment unit or

recycler 64.

A positioning controller 42 drives the "x", "y", and "z" tables, switches the

laser shutter 44 and powder feeder 32 on and off, and controls various gas flows.

Examples of commercially available positioning controllers which can be used

include, but are not limited to, Anorad™ and Laserdyne™ controllers.

Still with reference to Figure 1 , the deposition process is started by forming a

molten pool on a support means 46 such as a short segment of wire or rod that can be

cut off after deposition is complete. Typically the support is heated by the laser beam

24 without the powder feed turned on to preheat the support means 46, create melting,

and promote better adhesion of the first fused powder volume. Particulate material is

then formed into a conic particulate stream 26 and fed into the focal zone 30 and the wire or rod is deposited continuously until the desired length of material is generated.

The particulate material melts and resolidifies as heat is removed by conduction

through the base and by radiation from the deposition zone. Excess particulate

material which does not reach the focal zone 30 of the laser beam accumulates at the

base of the support means 46 and is collected by the powder collection recycler 60 for

reuse. Alternatively, the particulate material can be recycled directly back to the

powder mixing chamber 38 in a continuous loop process.

In a second embodiment of the invention a new means to continuously process

wire, rod or other elongated commercial shapes is described. Unlike conventional

continuous casting which relies on crucibles, rolls and molds to confine and shape the

melt, the invention process can be used to manufacture wire or rod in a single

continuous step.

This continuous processing embodiment of the invention method can be a

containerless process achieving melting and forming of the shape without contacting

other materials during formation of the wire or rod.. The shape is achieved and cooled

prior to spooling, cutting or packaging into lengths or spool sizes specified by the

customer.

A simplified continuous processing method in accordance with the invention,

shown in Figure 2, uses a fixed laser beam 24 (without fiber optic delivery), a single

axis of motion (z) without computerized numerical control, an inert but lower purity

inert atmosphere containment chamber 18 and a feed through seal 54 for removal of

material. With reference to Figure 2, a laser K) is positioned to focus through a laser

window 14 into a laser focusing head 22 so as to project a laser beam 24 into a

deposition zone 28. Simultaneously therewith, a relatively inert gas from a delivery

gas supply 40 is used to direct particulate matter from a powder feeder 32 in a

particulate stream 26 into the deposition zone 28. In the focal zone 30 in the

deposition zone 28 the laser beam 24 melts the particulate matter and forms the

elongated wire or rod 50 in the same manner described with reference to the first

embodiment of the invention. A means 48 for withdrawing wire or rod is positioned

below the deposition zone 28 so that the wire or rod product 50 is withdrawn from the

deposition zone 28 as it is formed.

A redirecting roller 52 can be used to allow withdrawal of the formed wire or

rod at an angle to the formation direction. A feed through seal 54 allows the formed

wire or rod 50 to be pulled from within the containment chamber JJ8 onto a take-up

spool 58. After the desired amount is wound onto the take-up spool 5_8, formed wire

may be cut in a cut off location 5_6 allowed between the feed through seal and the

take-up spool 58 and the new end started onto a new take-up spool.

Any unused particulate matter is caught in a powder collection recycler 60 and

recycled through a powder recycling loop 62 back into the powder feeder 32.

Another embodiment of the invention is a method of continuously producing

wire or rod having varying cross sections or of changing from one cross section or

specific chemical composition to another without stopping the process to retool. For

example, production of 0.045" wire can be seamlessly converted into production of

0.065" wire without stopping to change drawing dies or other equipment such as that required by conventional processing. This is accomplished by changing parameters

which affect the deposition rate, such as laser power, motion speed and powder flow

rate. The powder composition can be altered or changed by adding or refilling a new

type or grade of powder to the powder feed supply.

For example, three powder compositions can be fed sequentially or

simultaneously and combined with the laser energy and inert gas, and focused into a

deposition zone to produce a deposit. This deposit can be varied from one specific

chemical composition to another during continuous production of the wire or rod by

controlling the proportionate amount of each of the three powders going into the

mixture.

With reference to Figure 3, three separate powder feeders 32, 34 and 36 are

filled with the selected particulate materials and adjusted to release the desired

proportionate amounts by adjusting the rate of screw feeders and adjusting the

delivery gas pressure for each of the three separate powder feeders. The three

different feed materials from three separate powder feeders 32, 34 and 36 are

combined in a common powder mixing chamber 38. Relatively inert delivery gas

from a delivery gas source 40 is used to carry the powder from an eductor which is fed

by the common powder mixing chamber 38 to the delivery nozzle 16 in the form of a

powder/inert gas mix.

The inert delivery gas also serves to protect the molten pool and provides

cooling of the deposit. The inert delivery gas shields the deposition zone 28 from

oxygen or contamination by other unwanted materials. Manufacturing models (deposition paths) have been constructed for a number

of different rod diameter, shapes and translated into motion system program code

using a custom post processor specifically configured for a five-axis directed light

fabrication system operated in accordance with the present invention. Figures 4a, 4b,

4c and 4d show four exemplary deposition paths for deposition of successively larger

diameter wires, rods and bars.

Three-dimensional CAD/CAM models have been constructed using both

Pro/ENGINEER and ICEM software to create computerized numerical control files to

design cross sections of articles which could be continuously formed by the process of

this invention. Pro/ENGINEER software provides a highly integrated three-

dimensional solid modeling environment which has been recently employed in the

field of rapid prototyping. For example, Pro/ENGINEER software has been used by

plastics manufacturers to describe surface features by triangulation. These

triangulation files can be used to direct the formation of plastic shapes using

commercially available plastic prototyping machines. ICEM has been used

successfully to support three-dimensional CAD/CAM design needs and provides

extensive CAM programming capabilities.

Post processors can also be constructed to translate manufacturing models or

generic tool paths into multi-axis machine tool motion programs or machine-specific

code for deposition of particulate materials into elongated articles having specialty-

shaped diameters or circumferences in accordance with the present invention.

Process simulation can be performed to determine processing times and

cooling rates (and thus resultant microstructure) for various processing conditions. These simulations can be used to determine the effect of process variables such as

deposition speed, focal zone size and successive pass overlap. Process simulations

can also provide a means to analyze computational requirements such as computer

processing times, file sizes and data transfer rates. Solidification models can be used

to provide a means of predicting the microstructure of the deposited material and for

selecting the desired microstructures.

Simulations are also useful for investigating and developing the CAM

procedures necessary to generate wires or rods having surface features or diameter

configurations of increasing complexity. Commands and routines specific to the

directed light fabrication process of this invention can be integrated into the

deposition path for additional control. Customization of the CAD/CAM interface and

post-processing capability can be used to define and develop a software system

specific to the directed light fabrication process as applied to continuous processing.

Materials which can be used for the processes of this invention include both

easily processed materials and materials which would be difficult or impossible to

process using traditional or other non-conventional methods. Easily processed

materials which can be used in the practice of this invention include ferrous and

nonferrous metals such as steel aluminum, copper, silver, and gold and mixtures

thereof. For example, stainless steel is a useful material for processing into wires or

rods which have high strength, ductility, corrosion resistance and wear resistance.

Examples of materials that are generally difficult to process using previously

known methods include refractory metals such as tungsten, molybdenum, niobium, vanadium, rhenium, and tantalum; reactive metals such as titanium, zirconium and

hafnium; and toxic or hazardous materials such as beryllium, cobalt and nickel.

The inventive method and apparatus can be used to process precious metals

such as gold, silver, iridium, paladium, or platinum.

Blended or mixed powders may be fused into alloys or composite mixtures to

form materials not commercially available in any form, or to make otherwise

available materials more economically or with improved properties. Figure 5 shows a

metallographic cross section of a nickel based alloy rod made using a layered

deposition path. Figures 6a and 6b show, respectively, a metallographic cross section

and a longitudinal section of a titanium aluminum alloy rod.

Two examples of useful intermetallic compounds which can be made using the

present invention are nickel aluminide (NiAl) and molybdenum disilicide (MoSi₂),

neither of which is yet available commercially in wire or rod form.

A number of alloys and composite mixtures of materials which display

specific characteristics which may complicate or make difficult processing in

previously known methods can be processed easily using the present invention.

Examples of materials which can be processed into wire or rod using the present

invention include alloys and mixtures having abrasion, corrosion, wear or high

temperature resistance, high impact strength, brittleness or hardness, such as cobalt

based alloys and composite materials that contain hard fibers or particles such as

tungsten carbide.

Materials for the production of wire or rod in accordance with the present

invention can be chosen for the desired economics, facility of processing and desired properties. For example, Figure 7 shows wire segments of 316 stainless steel, pure

tungsten, nickel aluminide and molybdenum disilicide made in accordance with the

invention process. Although nickel aluminide and molybdenum disilicide are

generally brittle, and pure tungsten rods can be bent only once or twice, rods made of

stainless steel can be repeatedly bent, thus displaying ductility and the ability to spool

these materials.

In most embodiments of the invention, particulate material which is not fused

may be used again. Deposited material may be passed through a seal or vent allowing

sectioning and packaging outside the controlled purity growth environment.

Contaminants such as drawing lubricants or carbon pickup from drawing or

swaging dies can cause defects in subsequent use of the contaminated wires or rods.

Materials with properties which are made less desirable by picking up of contaminants

during conventional processing methods can be used in the practice of the present

invention. An example of such materials are the cobalt based filler materials used for

the re-conditioning of turbined blades. Pickup of lubricants and carbon during

conventional processing render these alloys useless for this type of repair and require

very slow and/or expensive alternative processing methods such as quartz casting.

Conventional casting methods are limited to casting rods of many millimeters in

diameter. When small diameter rods are required, these cast rods are then ground to

as small as 0.5 mm or less. The expensive grinding process creates large amounts of

waste and is a very costly way of producing wire or rods. The invention method

produces materials as good or better than those produced by the conventional methods

in a single step without waste. With use of this invention it is possible to manufacture wires and rods having

greater purity than the purity of the powder used for deposition because the heat and

melting occurring in the deposition zone can form gases of impurities which are then

driven off. For example, grade B powder can be refined during forming to produce

grade A wire.

The benefits of powder metallurgy techniques in the production of commercial

shapes are improved upon by the reduction in tooling and processing steps and quality

of resultant material deposit of the present invention. This invention makes many

powder metallurgy techniques obsolete by an even further reduction in processing

steps.

Flow charts comparing the steps of the invention method with the steps of

conventional wire or rod manufacture are shown in Figures 8a and 8b. It can be seen

that the invention significantly reduces the manufacturing steps.

Particulate material suitable for use in this invention can be made by re-

melting cast ingots and atomizing the molten metal by injecting gas, water,

mechanically spinning the liquid, or pouring the liquid onto a high speed spinning

plate. The chemically segregated ingot is randomized by this process of making

particulate material by atomization of re-melted cast ingots because the small powder

particles are distributed randomly, collected and reconsolidated during formation of

the elongated articles in accordance with the process of this invention.

Particulate material generally most suitable for use in this invention is usually

in larger particle sizes than those considered to be hazardous or carcinogenic due to

suspension of the particles in air. These larger particle sizes as well as a spherical shape are desirable due to the flow characteristics, though the use of smaller and/or

irregular shaped particles has been demonstrated using the present invention. In many

cases, such as processing of refractory metals, powder is the fundamental form of the

metal as a result of the extraction methods used to produce the metal. In other cases,

powder is already readily available commercially for powder metallurgy or thermal

spraying processes. Particle sizes which can be used in the practice of this invention

are generally in the range from about 1 micron to about 250 microns. Presently

preferred are particle sizes in the range from about 5 microns to about 150 microns.

Presently most preferred are particle sizes in the range from about 50 microns to about

100 microns, depending upon such parameters as powder morphology (spherical,

angular, irregular), material density, packing density and powder flow characteristics.

The raw material which does not become part of the wire or rod is easily

collected and reused without any additional processing or reprocessing. The

economic benefit of recycling unfused, uncontaminated material makes the invention

method attractive for processing of rare or expensive materials and makes the process

essentially waste free.

Inert gas purity suitable for use in the present invention is generally in the

range from less than 1 ppm to greater than 200 ppm oxygen and water, depending

upon purity and properties of product desired for the intended end use. Presently

preferred for making wire or rod from high strength, hard or refractory alloys such as

nickel-, cobalt- and tungsten-based alloys in gas purity in the range from about 5 ppm

to about 50 ppm oxygen and water. Materials less reactive to oxygen or nitrogen can

be formed in atmospheres containing higher concentrations of oxygen and water. The degree to which oxygen and water must be excluded depends upon the grade or

quality of product desired. For example, for making an A or B grade product, gas

purity ranging from about 50 to about 150 ppm generally can be used.

The ability to directly form metal parts by the directed light fabrication process

of this invention offers the advantage of structural integrity gained by achieving full

mechanical strength in the metal deposit. The process and apparatus of this invention

enables the manufacture of highly homogenous, pure forms of commercially useable

shapes in a manner which has improved cost effectiveness, speed, quality and ranges

of materials which may be processed.

Fully dense metal wires and rods having uniform surface texture, composition

and diameter can be made by deposition along a single vertical axis parallel to the axis

of the laser beam.

Wire or rod made by the laser deposition process of this invention is relatively

free of internal stresses in comparison to wire or rod made by traditional methods

because the continuous solid/liquid interface region produced in the invention process

yields fully dense components. This contrasts to other near net shape liquid powder

techniques (e.g., thermal spraying) in that a molten droplet does not impact onto a

solid substrate, and as a result, structural integrity degradations attributed to splat gaps

and other pore defects are absent.

Wire or rod made from the directed light fabrication process of this invention

has annealed properties, that is, its microstructure and metallurgical properties are

similar to those of articles which have been annealed. Figures 9a, 9b, and 9c, show

the powder used, microstructure as shown in a micrograph of a polished cross section and fracture surface of a wire made in accordance with the invention from 316

stainless steel. Figures 10a, 10b, and 10c, show the powder used, microstructure as

shown in a micrograph of a polished cross section and fracture surface of a wire made

in accordance with the invention from tungsten. Figures 11a, l ib, and 1 lc, show the

powder used, microstructure as shown in a micrograph of a polished cross section and

fracture surface of a wire made in accordance with the invention from nickel

aluminide, and figures 12a, 12b, and 12c, show the powder used, microstructure as

in accordance with the invention from molybdenum disilicide.

If the material of the wire or rod made from the directed light fabrication

process is heat-treatable, the properties of the wire or rod, such as strength, ductility,

fracture toughness, and corrosion resistance, can be modified by means of heat

treatment.

Surface melting of partially fused powder particles can be achieved by

directing a portion of the laser beam to remelt the surface after the initial deposition

process to create a smoother surface if desired.

There is no need to dispose of excess lubricants used in drawing wire or rod

and no need to clean lubricants from drawn wire or rod made by the directed light

fabrication processes of this invention because use of lubricants is unnecessary. The

waste stream resulting from the invention process is virtually eliminated. No

contamination is left on the surface of the wire or rod, so subsequent steps generally

used to remove contamination such as solvent cleaning or grinding are not required. However, grinding, rolling, swaging or other forming operations may be employed as

secondary operations to impart further characteristics to the deposited materials.

The following examples will demonstrate the operability of the invention.

EXAMPLE I

Fifty %" diameter rods were made with equipment set up as shown in Figure

1.

One gallon of particulate Inconel™ 690 powder (a nickel based alloy containing about

60% nickel, and minor amounts of iron and cobalt) commercially available from Inco

Alloys, Inc. was placed into an Accurate™ 1/3 ft³ capacity powder feeder. The

Inconel™ powder ranged in spherical particle size from 44 microns to 149 microns.

The powder was fed by a screw-type feed to an eductor where argon delivery gas was

used to take the powder to a splitter which divided the powder into 8 streams in tubes

connected to a nozzle at the laser head.

At the laser head the 8 multiple streams of powder were delivered so as to

achieve a precise focus of the powder streams at a position cofocal to the laser beam.

A 5 -axis Laserdyne™ 94 directed light fabrication system controller

(commercially available from Laserdyne in Eden Prarie, MN) was used to articulate

the laser head with respect to the deposited material so that continuous fusion and

build up of material was achieved.

The controller used a Intel 486 PC type computer to control the 5-axis drive

control boards and the control laser by means of an RS-232 serial port. It had a graphical user interface to allow setup and execution of the machine and motion

control program.

A Lumonics™ two-kilowatt continuous wave Nd:YAG laser, commercially

available from Lumonics in Livonia, MI was used to generate the 1.06 micron wave

length laser energy to melt the powder and provide a focused laser spot, accurate

enough to form small wires.

Deposition of the parts was achieved by using 300 watt laser power, 45 inch

per minute travel speed, a powder feed of 7 to 15 grams per minute, and 3.44 standard

liters per minute of argon gas. Atmosphere purity in the environment chamber was

maintained at 50 ppm oxygen and water. Overlap of one circular pass upon the next

adjacent pass was 0.12". The increment of vertical movement used to build up the

shaped cylinder was 0.15" per layer.

The apparatus was set up as shown in Figure 1 in the manner described in the

specification hereof.

Commercially available CAD-CAM software (ProENGINEER from

Parametric Technology, Waltham, Massachusetts) was used to produce a three-

dimensional solid model of a rod from which deposition path location files were

generated. The deposition path location files were input into a custom made post

processor program using a NC POST PLUS™ software tool commercially available

from CAD/CAM Resources, Inc., Rio Rancho, NM. A circular deposition path type

such as that shown in Figure 4c was used. The post processor was used for translating the deposition path location file

into motion commands specific to the 5 -axis directed light fabrication system

controller.

An example of the computerized numerical control (CNC) output file used is

shown in Table 1. This computer program was used to fabricate a 0.75" outside

diameter, 0.50" long rod. The computer program was produced using CAD CAM

software.

TABLE 1

CNC Output File for Deposition Path

Commands Comments

#G1 ; linear interpolation

F45 ; feed rate inches per minute

G92XYZ ; reset XYZ to 0

#10G90 ; absolute positioning

#15G70 ; inch programming

#20G07 ; constant velocity

TABLE 1 (continued)

Commands Comments

V1=0 ; counter variable

V2= 015 ; z increment

V3=0.750/V2/4 ; path variable

Q5RV3 ; run subroutine 5 V3 times MO program stop

M5S5 start of subroutine 5

V1=V1+V2 increment variable VI

#280X.366ZV1 move

G4X1 dwell

M100 shutter open, beam on, powder on

#285G3I-.366J0. motion commands follow

#45G3I-.366J0.

#50X.351

#55G3I-.351J0.

#60X336

#65G3I-.36J0.

#70X.321

#75G3I-.321J0.

#80X306

#85G2I-.306J0.

#90X.291

#95G3I-.291J0.

#100X.276

TABLE 1 (continued)

Commands Comments

#105G3I-.276J0.

#110X.261

#115G3I-.261J0.

#120X.246

#125G3I-.246J0.

#130X.231 #135G3I-.231J0. #140X.216 #145G3I-.216J0. #150X.201 #155G3I-.201J0.

#160X.186 #165G3I-.186J0. #170X.171 #175G3I-.171J0. #180X.156

#185G3I-.156J0. #190X.141 #195G3I-.141J0. #200X.126 #205G3I-.126J0.

#210X.l l l #215G3I-.111J0.

TABLE 1 (continued)

Commands Comments

#220X.096

#225G3I-.096J0.

#230X.081 #235G3I-.081J0.

#240X.066 #245G3I-.066J0. #250X.051 #255G3I-.051J0. #260X.041 #265G3I-.041J0.

V1=V1+V2

X.031

G3I-.031J0.

X.016

G31-.016J0.

X-.016

ZV1

V1=V1+V2

#280X-.366

G4X1

M100

#285G3I.366J0.

#50X-.351

#55G3I.351J0.

TABLE 1 (continued)

Commands Comments

#60X-.336

#65G3I.366J0.

#70X-.321

#75G3I.321J0.

#80X-.306

#85G3I.306J0.

#90X-.291

#95G3I.291J0.

#100X-.276

#105G3I.276J0.

#110X-.261 #115G31.261J0.

#120X-.246

#125G3I.246J0.

#130X-.321 #135G3I.231J0.

#140X-.216

#145G3I.216J0.

#150X-.201

#155G3I.201J0. #160X-.186

#165G3I.186J0.

#170X-.171

#175G3I.171J0.

TABLE 1 (continued)

Commands Comments

#180X-.156 #185G3I.156J0. #190X-.141

#195G3I.141J0. #200X-.126 #205G3I.126J0. #210X-.l l l #215G3I.111J0.

#220X-.096 #225G3I.096J0. #230X-.081 #235G3I.08J0. #240X-.066 #245G3I.066J0.

#250X-.051

#255G3I.051J0.

#260X-.041

#265G3I.041J0.

V1=V1+V2

X-.031

TABLE 1 (continued)

Commands Comments

G3I.031J0. X-.016 G3I.16J0. M101 ; shutter closed, beam off, powder off

M6 ; end of subroutine

The post processor was also used to add machine commands to control the

laser beam power, laser shutter, powder flow and part speed and written to the CNC

output file. A 1/4" thick, 6" diameter steel plate was used as a starting support. The

steel plate starting support was placed into the inert environment chamber and aligned

with the motion system axis.

The CNC file was loaded into the directed light fabrication system controller

memory and executed to form uniform, fully dense rods having a 3/4" diameter.

Each of the rods produced was separated from the starting support by saw

cutting.

The rod samples produced were cut from the steel plate using a metal saw and

sliced into 3/4" tall half sections . The sections of nickel alloy rod were mounted in 1 "

diameter standard metallographic mounts using epoxy. The cut surfaces of the rods

were then polished and etched, to reveal the microstructures of the rods. The microstructures of the rods were examined at magnifications ranging from 10X to

600X. The examination showed that the rods produced were fully dense as shown in

the cross section of Figure 5. The deposited layers showed up in the structure and

were delineated by changes in the surface of the structure at the layer boundaries. The

microstructure shows the previous layer corresponding with the step up height in the

vertical Z direction of the laser beam relative to the deposit. Continuous epitaxial

growth was found across many layers.

The microstructural development in the samples processed in accordance with

this invention typically displayed continuous morphologies as well as refined

segregation features, indicating a constant solid/liquid interface and rapid

solidification kinetics.

EXAMPLE II

A set of runs was made using the invention process to make fifty

titanium/aluminum alloy rods in a range of diameters from 0.050" to 0.150".

Equipment was set up as diagrammed in Figure 1 and described in Example I.

A Lumonics™ two-kilowatt continuous wave 1.06 micron Nd: YAG laser was

set to generate a 235 watt laser beam which was focused co-axially with a stream of -

180 to +325 mesh particle size spherical powder commercially available from

Crucible Research in Oakdale, PA.

A spiral deposition path having a 0.050" diameter circular motion/revolution

was programmed directly into the Laserdyne 94 controller. Other systems parameters were: 50 inches per minute motion, 5 to 50 ppm oxygen and water content of the

atmosphere in the box, 3.4 slpm argon delivery gas, 15 g/min powder flow.

The powder was 48% titanium, 48% aluminum, 2% niobium and 2%

cromium.

Some of the rods were grown vertically using a single axis of motion (without

use of the spiral tool path) at 122 watts at a linear speed of 4 to 16 inches per minute.

Machine commands were edited directly into the console of the motion

controller and laser controller interface to start the flow of powder and laser energy

and to begin the motion.

A helical deposition path was programmed directly into a Laserdyne™ 94

motion controller to form a titanium/aluminum alloy rod of 0.100" diameter.

Using the helical deposition path program, a uniform density, 0.125" diameter

titanium/aluminum rod was also formed. Although this very hard material would be

extremely difficult to process by existing conventional methods, the

titanium/aluminum rod was relatively easy to form using the invention process.

The 13" long rods were observed to have a uniform cross sectional area and a

surface of partially fused powder. Some rods were centerless ground to demonstrate

that the rods could be reduced in size to rods having cross sectional diameters as small

as 0.028".

Metallographic sectioning and microscopic inspection as described in Example

I was used to determine full density. No discoloration of the surface was observed;

lack of coloration indicated a pure, uncontaminated, as deposited surface. Epitaxial grain growth was observed along the length of the rod by

microscopic inspection at a magnification of 400X.

The samples produced in this example were also tested using a scanning

electron microscope electron dispersive spectroscopy system to determine the

chemistry of the samples. This test showed that the samples had the same

proportionate amounts of materials as were introduced into the process in powder

form. Therefore, there had been no preferential vaporization of the starting materials

during processing. This demonstrated that the chemical composition of the starting

material was not affected by this method of processing.

Figures 6a and 6b show, respectively, a cross section and longitudinal section

of the rod formed in this example.

EXAMPLE III

Equipment was set up as depicted in Figure 1 , in the manner described in

Example I.

A single axis of motion was used to fuse pure tungsten into wire. A pulsed

Nd:YAG laser (Lumonics™ 701) was used along with an Anorad™ II motion

controller to achieve semi-automatic process control. Commands were entered

manually into the laser and motion system as well as manual operation of the gas and

powder flow control.

The atmosphere purity used for this example was 5 ppm oxygen and water.

The support structure used to begin wire deposition was a metal plate from

which wires were cut off after growth. Rods were grown using 100 watts of power at a speed of 5 inches per minute

and a powder feed rate of 5 grams/minute. Spherical tungsten powder was used in a

size range from 5 microns to 50 microns.

The samples produced in this example were subjected to simple bending of

greater than 90° to demonstrate the ductility of the soft annealed microstructure of the

tungsten deposit. After 1 to 2 bends, the rods broke. The fracture surfaces were

examined with a scanning electron microscope at 1500X magnification. No voids or

discontinuities were observed.

The ductility demonstrated by the number of bends possible before breaking of

the invention sample rods was clearly superior to similar pure tungsten welding rods

of the same dimensions made by conventional methods, because the conventional

tungsten welding rods could not be bent at all without breaking.

The tungsten rod samples produced in this example were metallographically

tested for full density in the manner described in Example I. The tungsten deposited

in accordance with the invention as described in this example was determined to be

fully dense by metallographic cross sectioning.

While the apparatuses, articles of manufacture, methods and compositions of

this invention have been described in detail for the purpose of illustration, the

inventive apparatuses, articles of manufacture, methods and compositions are not to

be construed as limited thereby. This patent is intended to cover all changes and

modifications within the spirit and scope thereof. INDUSTRIAL APPLICABILITY The invention is useful for making a large variety of wire, rod or other elongated shapes from a variety of materials including materials not commercially available or specialty materials such as refractory metals. Articles made in accordance with the invention can be used for such diverse applications as filler wires for repair of aircraft, aerospace and marine components, precision hard facing, refractory components for space applications, heating elements, filaments, emitters, high temperature furnace hardware, and wherever wires or rods with specialty components or unusual cross sections are needed.

Claims

WHAT IS CLAIMED IS:

1. A method of forming an elongated article from materials in particulate form, said method comprising:

(a) defining the shape and dimensions of an article; (b) providing a means for introducing particulate material into a deposition zone;

(c) creating a deposition path and control commands effective to form said article by deposition of molten material;

(d) focusing a laser beam at a location within said deposition zone;

(e) providing particulate material to said deposition zone; (f) forming a pool of molten material in said deposition zone by melting a portion of an article support and said particulate material by means of energy provided by said laser beam;

(g) depositing molten material from said deposition zone on said article support at points along a first portion of said deposition path by moving said deposition zone along said deposition path, where said molten material solidifies after leaving said deposition zone, in order to form a portion of said article which is adjacent to said article support;

(h) forming a pool of molten material in said deposition zone by melting a portion of said partially formed article and said particulate material by means of energy provided by said laser beam;

(i) depositing molten material from said deposition zone at points along a second portion of said deposition path by moving said deposition zone along said deposition path, where said molten material solidifies after leaving said deposition zone, in order to continue formation of said article; and (j) controlling flow of particulate material into said deposition zone, energy density of said laser beam, and focal position of said laser beam by means of said control commands as deposition takes place.

2. A method of forming an elongated article from materials in particulate form, said method comprising: (a) defining the shape and dimensions of an article;

(b) providing a means for introducing particulate material into a deposition zone;

(c) creating a deposition path and control commands effective to form said article by deposition of molten material; (d) focusing a laser beam at a location within said deposition zone;

(e) providing particulate material to said deposition zone;

(f) fo╧Çning a pool of molten material in said deposition zone by melting a portion of an article support and said particulate material by means of energy provided by said laser beam;

(g) depositing molten material from said deposition zone on said article support at points along a first portion of said deposition path by moving said article support away from said deposition zone as said molten material solidifies after leaving said deposition zone, in order to form a portion of said article which is adjacent to said article support;

(h) forming a pool of molten material in said deposition zone by melting a portion of said partially formed article and said particulate material by means of energy provided by said laser beam; (i) depositing molten material from said deposition zone at points along a second portion of said deposition path by moving said partially formed article away from said deposition zone in accordance with said deposition path as said molten material solidifies after leaving said deposition zone, in order to continue formation of said article; and

(j) controlling flow of particulate material into said deposition zone, and energy density of said laser beam, focal position of said laser beam, and speed of withdrawal of said article being formed from said deposition zone by means of said control commands as deposition takes place.

3. A method as recited in Claim 1 wherein said method is carried out in a controlled atmosphere.

4. A method as recited in Claim 2 wherein said method is carried out in a controlled atmosphere.

5. A method as recited in Claim 1 wherein said deposition zone is exposed to a magnetic field.

6. A method as recited in Claim 2 wherein said deposition zone is exposed to a magnetic field.

7. A method as recited in Claim 1 wherein any particulate material escaping unused from said deposition zone is recycled back to a particulate material supply for supplying said deposition zone.

8. A method as recited in Claim 2 wherein any particulate material escaping unused from said deposition zone is recycled back to a particulate material supply for supplying said deposition zone.

9. A method as recited in Claim 1 wherein said control commands for said deposition path are CAD CAM commands:

#G1

F45 G92XYZ

#10G90

#15G70

#20G07

V1=0 V2=.015

V3=0.750/V2/4

Q5RV3

MO

M5S5 V1=V1+V2

#280X.366ZV1

G4X1

M100 #285G3I-.366J0. #45G3I-.366J0. #50X.351 #55G3I-.351J0. #60X.336

#65G3I-.36J0. #70X.321 #75G3I-.321J0. #80X.306 #85G2I-.306J0.

#90X.291 #95G3I-.291J0. #100X.276 #105G3I-.276J0. #110X.261

#115G3I-.261J0. #120X.246 #125G3I-.246J0. #130X.231 #135G3I-.231J0.

#140X.216 #145G3I-.216J0. #150X.201 #155G3I-.201J0. #160X.186

#165G3I-.186J0. #170X.171 #175G3I-.171J0. #180X.156 #185G3I-.156J0.

#190X.141 #195G3I-.141J0. #200X.126 #205G3I-.126J0. #210X.l l l

#215G3I-.111J0. #220X.096 #225G3I-.096J0. #230X.081 #235G3I-.081J0.

#240X.066 #245G3I-.066J0. #250X.051 #255G3I-.051J0. #260X.041 #265G3I-.041J0.

V1=V1+V2

X.031

G3I-.031J0. X.016

G31-.016J0.

X-.016

ZV1

V1=V1+V2 #280X-.366

G4X1

M100

#285G3I.366J0.

#50X-.351 #55G3I.351J0.

#60X-.336

#65G3I.366J0.

#70X-.321

#75G3I.321J0. #80X-.306

#85G3I.306J0.

#90X-.291

#95G3I.291J0.

#100X-.276 #105G3I.276J0.

#110X-.261

#115G31.261J0.

#120X-.246

#125G3I.246J0. #130X-.321

#135G3I.231J0.

#140X-.216

#145G3I.216J0.

#150X-.201 #155G3I.201J0.

#160X-.186

#165G3I.186J0.

#170X-.171

#175G3I.171J0. #180X-.156

#185G3I.156J0.

#190X-.141

#195G3I.141J0.

#200X-.126 #205G3I.126J0. #210X-.l l l #215G3I.111J0. #220X-.096 #225G3I.096J0. #230X-.081

#235G3I.08J0. #240X-.066 #245G3I.066J0. #250X-.051 #255G3I.051J0.

#260X-.041 #265G3I.041J0. V1=V1+V2 X-.031

G3I.031J0. X-.016 G3I.16J0. M101 M6

10. A method as recited in Claim 2 wherein said control commands for said deposition path are CAD CAM commands:

#G1 F45

G92XYZ

#10G90

#15G70

#20G07 N1=0

V2= 015

V3=0.750/V2/4

Q5RV3

MO M5S5

V1=V1+V2

#280X.366ZV1

G4X1

M100 #285G3I-.366J0.

#45G3I-.366J0.

#50X.351

#55G3I-.351J0.

#60X.336 #65G3I-.36J0.

#70X.321

#75G3I-.321J0.

#80X306

#85G2I-.306J0. #90X.291

#95G3I-.291J0.

#100X.276

#105G3I-.276J0.

#110X.261 #115G3I-.261J0.

#120X.246

#125G3I-.246J0.

#130X.231 #135G3I-.231J0.

#140X.216

#145G3I-.216J0.

#150X.201 #155G3I-.201J0.

#160X.186

#165G3I-.186J0.

#170X.171

#175G3I-.171J0. #180X.156

#185G3I-.156J0.

#190X.141

#195G3I-.141J0.

#200X.126 #205G3I-.126J0.

#210X.l l l

#215G3I-.111J0.

#220X.096

#225G3I-.096J0. #230X.081

#235G3I-.081J0.

#240X.066

#245G3I-.066J0.

#250X.051 #255G3I-.051J0.

#260X.041

#265G3I-.041J0.

V1=V1+N2

X.031 G3I-.031J0.

X.016

G31-.016J0.

X-.016

ZV1 V1=V1+V2

#280X-.366

G4X1

M100

#285G3I.366J0. #50X-.351

#55G3I.351J0.

#60X-.336

#65G3I.366J0.

#70X-.321 #75G3I.321J0. #80X-.306 #85G3I.306J0. #90X-.291 #95G3I.291J0. #100X-.276

#105G3I.276J0. #110X-.261 #115G31.261J0. #120X-.246 #125G3I.246J0.

#130X-.321 #135G3I.231J0. #140X-.216 #145G3I.216J0. #150X-.201

#155G3I.201J0. #160X-.186 #165G3I.186J0. #170X-.171 #175G3I.171J0.

#180X-.156 #185G3I.156J0. #190X-.141 #195G3I.141J0. #200X-.126

#205G3I.126J0. #210X-.l l l #215G3I.111J0. #220X-.096 #225G3I.096J0.

#230X-.081 #235G3I.08J0. #240X-.066 #245G3I.066J0. #250X-.051

#255G3I.051J0. #260X-.041 #265G3I.041J0. V1=V1+V2 X-.031

G3I.031J0. X-.016 G3I.16J0. M101 M6

11. An apparatus for forming an article from materials in particulate form, said apparatus comprising:

(a) a means for defining the shape and dimensions of an article, said means being capable of creating a deposition path and control commands effective to form an article by depositions of molten material;

(b) a means for introducing particulate material into a deposition zone;

(c) a laser positioned to focus a laser beam into said particulate material in said deposition zone; (d) a means for supporting and drawing said article away from said deposition zone; and

(e) a means for controlling flow of said particulate material, energy density of said laser beam, focal position of said laser beam, and speed of withdrawal of an article being formed from said deposition zone by using said control commands.

12. An apparatus for forming an article from materials in particulate form, said apparatus comprising:

(a) a means for defining the shape and dimensions of an article, said means being capable of creating a deposition path and control commands effective to form an article by depositions of molten material; (b) a means for introducing particulate material into a deposition zone;

(c) a laser positioned to focus a laser beam into said particulate material in said deposition zone;

(d) a means for supporting said article in said deposition zone;

(e) a means for moving said deposition zone along said deposition path; (f) a means for controlling flow of said particulate material, energy density of said laser beam, focal position of said laser beam, and speed of withdrawal of an article being formed from said deposition zone by using said control commands.