Design for Low-Cost Gas Metal Arc Weld-Based Aluminum 3-D Printing

Additive manufacturing, commonly known as 3-D printing, has the potential to change the state of manufacturing across the globe. Parts are made, or printed, layer by layer using only the materials required to form the part, resulting in much less waste than traditional manufacturing methods. Additive manufacturing has been implemented in a wide variety of industries including aerospace, medical, consumer products, and fashion, using metals, ceramics, polymers, composites, and even organic tissues. However, traditional 3-D printing technologies, particularly those used to print metals, can be prohibitively expensive for small enterprises and the average consumer. A low-cost open-source metal 3-D printer has been developed based upon gas metal arc weld (GMAW) technology. Using this technology, substrate release mechanisms have been developed, allowing the user to remove a printed metal part from a metal substrate by hand. The mechanical and microstructural properties of commercially available weld alloys were characterized and used to guide alloy development in 4000 series aluminum-silicon alloys. Wedge casting experiments were performed to screen magnesium, strontium, and titanium boride alloying additions in hypoeutectic aluminum-silicon alloys for their properties and the ease with which they could be printed. Finally, the top performing alloys, which were approximately 11.6% Si modified with strontium and titanium boride were cast, extruded, and drawn into wire. These wires were printed and the mechanical and microstructural properties were compared with those of commercially available alloys. This work resulted in an easier-to-print aluminum-silicon-strontium alloy that exhibited lower porosity, equivalent yield and tensile strengths, yet nearly twice the ductility compared to commercial alloys

A Case for Weakening Patent Rights

(Excerpt) In Part I, this Article introduces the new and emerging technologies, including the Internet, cloud computing, three-dimensional (“3D”) printing, and synthetic biology, which will bring this radical change. Part II provides an overview of the innovation cycle, including the stages of basic research, inventing and prototyping, product development, marketing, and distribution. It also describes, in detail, how these new technologies are dramatically lowering the costs and risks of all stages in the innovation cycle. Part III considers how lawmakers might adapt patent law to account for the new age of innovation and its lower costs of innovation. This Article explores both the magnitude of the change and the method by which that change should be accomplished; specifically, it analyzes various factors that might affect the magnitude of the change to patent strength, such as nonmonetary incentives to innovate, decreased costs of copying innovations, and concerns about U.S. companies’ competitiveness in a global marketplace. After considering these factors, this Article recommends that lawmakers weaken patents by at least twenty-five to fifty percent. Such a change would not only account for decreased costs of innovation, but also would be large enough for the change to be unequivocally felt and studied. To accomplish this reduction in patent strength this Article explores shortening the patent term, but with the understanding that to do so would be politically difficult. Thus, it recommends dramatically raising patent maintenance and renewal fees for the end portion of patents’ lives. Finally, this Article also briefly explores doctrinal changes that could weaken patents in specific technology sectors and explain why we consider them a second-best option

A Case for Weakening Patent Rights

This Article contributes to the patent debate by observing that new and emerging technologies are radically altering the relative costs and benefits of the patent system. Although analysts cannot measure the patent system\u27s numerous absolute costs and benefits, this Article demonstrates that new and emerging technologies are significantly reducing the research, development, and commercialization costs ( innovation costs ) that are used by adherents to the incentive and prospect theories to justify the patent system\u27s existence. All things being equal, if significantly, the relative need for the patent system has decreased and will continue to decrease. Thus, this Article argues that patents should be weakened significantly-by at least twenty-five to fifty percent. To support this claim, this Article takes an interdisciplinary approach out of appreciation for the fact that innovation spans many disciplines: Two of the authors are scientists with extensive expertise in three-dimensional printing, and the remaining author is a law professor who is an expert on patent law. Altogether, this Article offers a thorough catalog of new and emerging technologies and their effects, both general and specific, on innovation costs and the patent system

A Case for Weakening Patent Rights

(Excerpt) In Part I, this Article introduces the new and emerging technologies, including the Internet, cloud computing, three-dimensional (“3D”) printing, and synthetic biology, which will bring this radical change. Part II provides an overview of the innovation cycle, including the stages of basic research, inventing and prototyping, product development, marketing, and distribution. It also describes, in detail, how these new technologies are dramatically lowering the costs and risks of all stages in the innovation cycle. Part III considers how lawmakers might adapt patent law to account for the new age of innovation and its lower costs of innovation. This Article explores both the magnitude of the change and the method by which that change should be accomplished; specifically, it analyzes various factors that might affect the magnitude of the change to patent strength, such as nonmonetary incentives to innovate, decreased costs of copying innovations, and concerns about U.S. companies’ competitiveness in a global marketplace. After considering these factors, this Article recommends that lawmakers weaken patents by at least twenty-five to fifty percent. Such a change would not only account for decreased costs of innovation, but also would be large enough for the change to be unequivocally felt and studied. To accomplish this reduction in patent strength this Article explores shortening the patent term, but with the understanding that to do so would be politically difficult. Thus, it recommends dramatically raising patent maintenance and renewal fees for the end portion of patents’ lives. Finally, this Article also briefly explores doctrinal changes that could weaken patents in specific technology sectors and explain why we consider them a second-best option

Technical solar photovoltaic potential of scaled parking lot canopies: A case study of walmart U.S.A.

Solar photovoltaic (PV) technology can provide sustainable power for the growing global population in cities, but it demands considerable land area. This is a challenge for densely populated cities. However, the stranded assets of non-productive parking lots areas can be converted to solar farms with PV canopies, enabling sustainable electricity generation while preserving their function to park automobiles. This study provides a method for determining the technical and economic potential for converting a national scale retail company’s parking lot area to a solar farm. First, the parking lot area for the company is determined and divided into zones based upon solar flux using virtual maps. Then the potential PV yield in each zone is calculated. A sensitivity analysis is performed on the price per unit power installed, solar energy production as a proxy for conversion efficiency, electricity rates and revenue earned per unit area. To demonstrate this method, analysis of Walmart Supercenters, USA is presented as a case study. The results show solar canopies for parking lot areas are a profitable as well a responsible step in most locations and there is significant potential for sustainable energy deployment in cities by other similar retailers using solar PV canopies

Integrated voltage—current monitoring and control of gas metal arc weld magnetic ball-jointed open source 3-D printer

To provide process optimization of metal fabricating self-replicating rapid prototyper (RepRap) 3-D printers requires a low-cost sensor and data logger system to measure current (I) and voltage (V) of the gas metal arc welders (GMAW). This paper builds on previous open-source hardware development to provide a real-time measurement of welder I-V where the measuring circuit is connected to two analog inputs of the Arduino that is used to control the 3-D printer itself. Franklin firmware accessed through a web interface that is used to control the printer allows storing the measured values and downloading those stored readings to the user’s computer. To test this custom current and voltage monitoring device this study reports on its use on an upgraded all metal RepRap during the printing of aluminum alloy (ER1100, ER4043, ER4943, ER4047, and ER5356). The voltage and current data were analyzed on a per alloy basis and also layer-by-layer in order to evaluate the device’s efficacy as a monitoring device for 3-D printing and the results of the integrated design are discussed

Free and open-source control software for 3-D motion and processing

RepRap 3-D printers and their derivatives using conventional firmware are limited by: 1) requiring technical knowledge, 2) poor resilience with unreliable hardware, and 3) poor integration in complicated systems. In this paper, a new control system called Franklin, for CNC machines in general and 3-D printers specifically, is presented that enables web-based three dimensional control of additive, subtractive and analytical tools from any Internet connected device. Franklin can be set up and controlled entirely from a web interface; it uses a custom protocol which allows it to continue printing when the connection is temporarily lost, and allows communication with scripts

Hypoeutectic aluminum-silicon alloy development for gmaw-based 3-D printing using wedge castings

Alloy development can simplify low-cost gas metal arc weld (GMAW)-based 3-D printing by making it easier to print quality parts with minimal metallurgical or welding experience. Previous work found good properties in aluminum alloys, particularly in the aluminum-silicon 4943 (Al-5.5%Si-0.4%Mg) and 4047 (Al-11.6%Si) alloys. These alloys were easy to print, but could benefit from alloying to increase ductility and to minimize or redistribute porosity. The purpose of this study was to modify 4943 and 4047 alloys and rapidly screen their performance for use as feedstock for improved 3-D printability. The 4047-and 4943-based alloys were modified with additions of magnesium, strontium, titanium boride, and combinations thereof. Wedge-shaped castings were used to efficiently screen alloying additions over the same ranges of solidification rates as those observed in GMAW-based 3-D printing. The alloying additions were most effective at modifying the high-silicon 4047 alloy, whereas no change in microstructure was observed in the low-silicon 4943 alloy. Strontium was an effective modifier of the high-silicon alloy. Titanium boride was not observed to have a grain-refining effect on aluminum dendrites on its own, although the combination of strontium and titanium boride produced the most refined eutectic structure in the high-silicon alloy. Future work should evaluate the singular effects of strontium, titanium boride, and the combination of strontium and titanium boride additions in weld-based 3-D printing

In situ formation of substrate release mechanisms for gas metal arc weld metal 3-D printing

This study provides an in-depth investigation into low-cost and no-cost substrate release mechanisms that allow gas metal arc weld 3-D printed ER4043 aluminum and ER70S-6 steel parts to be removed from a reusable print substrate with minimal energy. Aluminum oxide, boron nitride, and titanium nitride coatings were evaluated as possible substrate release agents for aluminum printing. Additionally, the in situ formation of substrate release agents such as intermetallics and oxides were tested for both aluminum and steel printing. Testing was performed with a modified Charpy impact tester to remove 3-D printed metal parts from an 1100 aluminum or A36 low carbon steel print substrate to assess the impact energy required for removal. Specimen porosity was measured prior to sectioning and microstructural analysis, hardness traverses were measured across the specimens, and the elastic and shear moduli of the parts were analyzed via ultrasonic methods. All of the employed substrate release mechanisms minimized weld penetration and, in some instances, formed a brittle phase with the print substrate that allowed the specimens to be removed with minimal impact energy. These results thus provide methods with the removal of metal 3-D printed parts from print substrates with no specialized tooling or equipment conducive to distributed manufacturing

Tensile and fatigue behavior of novel dissimilar resistance spot welds of AA5754 to steels: interplay of intermetallic layer, weld nugget diameter and notch root angle

AA5754 sheet was resistance spot welded (RSW) to high-strength low-alloy (HSLA) steel sheet and low carbon steel (LCS) sheet respectively using multi-ring domed (MRD) electrodes and multiple solidification weld schedules. The confluence of the intermetallic compound layer, weld nugget diameter, and notch root angle are delineated. The results demonstrated that elevated Mn content (0.634%) in the HSLA steel promoted the formation of a thinner and more uniform IMC layer in AA5754-HSLA stack-ups when compared to the LCS, comprised of a lower Mn content (0.130%), in the AA5754-LCS stack-ups. Diluting the alloy content by changing the HSLA sheet to LCS sheet in AA5754-steel RSWs softened the aluminum weld nugget. Fatigue results demonstrated that fatigue life in Al-steel spot welds is greater when compared to the aluminum sheet joined to itself in the tensile shear configuration. Fatigue life was greater for the positive polarity AA5754-HSLA steel RSWs than for the AA5754-LCS. While weld nugget diameter dominates weld fatigue life, manipulation of the weld notch root angle enables additional fatigue life control. To enhance fatigue life, a large notch root angle is beneficial