William J. Emblom

Emblom Engineering

Friction stir processing is being used to improve characteristics of advanced manufactured process by improving the strength and ductility of material, joining, surface characteristics, and alloying. In addition, friction stir processing may be used as a first step for recycling metallic waste. The authors are interested in the friction stir proces...

As part of the efforts to produce robust, cost effective bipolar plates, it is necessary to evaluate the forming characteristics of potential materials under consideration. For this work the relationship between strain and deformation induced surface roughness was investigated for channels made from AISI 304 stainless steel and AISI 1010 mild steel...

Friction stir processing has become a popular method for welding, surface treatment, and more recently for producing extrusions such as tubing and cylinders. Currently, the extrusions produced usually have diameters from 6 to 19 millimeters because they are being produced in tooling that must be placed in conventional CNC mills located within unive...

Friction stir processing has become a popular method for welding, surface treatment, and more recently for producing extrusions such as tubing and cylinders. Currently, the extrusions produced usually have diameters from 6 to 19 millimeters because they are being produced in tooling that must be placed in conventional CNC mills located within unive...

Reducing fuel consumption has been a driving factor for researchers and manufacturers to continually develop improved methods for reducing the weight of automobiles or lightweighting. These vehicle lightweighting demands have directed researchers to look to using materials that are typically more difficult to manufacture in their studies. As a resu...

An investigation was performed examining the effects of draw beads and blank holder forces on local forces in various regions of a stamp forming process that produced oval aluminum panels. The results showed that provided there was sufficient blank holder forces to prevent wrinkling, the regions with draw beads were affected more by draw bead heigh...

Preliminary work on a new research project frequently entails proof-of-concept tests and modeling. The current project is investigating friction stir processing to produce small macroscale aluminum solid cylinders. The tooling was designed to be used in a 2-HP Bridgeport Mill for initial proof of concept tests and then later used in a CNC mill. The...

In the present work the relationship between deformation and deformation induced surface roughness of 100 micron thick annealed AISI 304 stainless steel was investigated at the meso scale. This work is a continuation of the previous work by the authors where roughness values were determined at the apex of the bulge test samples at micro scale. The...

Friction stir back extrusion (FSBE) has been identified as a manufacturing method for producing tubing with both stronger and more ductile tubing for applications such as hydroforming, biomedical, energy, and MEMS. Additionally, FSBE has been identified as a technology that can be potentially down scaled. However, the process is still not fully und...

A microscale/multiscale tube hydroforming system including tooling and controls is being designed and implemented at the University of Louisiana at Lafayette as part of a collaborative effort with Michigan Technological University. The sealing system demonstrates the evolution of the flared tube ends approach for tube end sealing to a spherical met...

Friction stir back extrusion has recently been identified as a method for manufacturing stronger, more ductile seamless tubes. However, most of the work to date has investigated tubes with low length to diameter ratios and there has been little work investigating the change in grain through the thickness of the tube wall. The current project presen...

Methods for improving the robustness of panel forming including the introduction of process sensing and feedback and control has resulted in significant gains in the quality of parts and reduced failures. Initial efforts in implementing closed-loop control during panel forming used active tool elements to ensure that the total punch force followed...

Due to the miniaturization of products, new or modified processes are required to create small components. With the development of these new processes, it is also important to establish methods to evaluate the mechanical properties of the materials used in these components. These properties are necessary for accurately creating representative predi...

Friction stir back extrusion has recently been identified as a method for manufacturing stronger, more ductile seamless tubes. The long term goal of the project described here is to miniaturize the process in order to produce highly ductile microscale tubes for biomedical, microscale heat exchanger, and fuel cell manufacturing applications. The pro...

In this study, the relationship between surface topography and strain was established for annealed 0.2 mm thick AISI 304 stainless steel sheet that had been hydroformed. The effect of the die diameter on the surface topography was also examined. Sheets were bulged using stepwise application of hydraulic pressure; forcing the sheet metal through 5 m...

Micro- and multiscale material properties must be considered when manufacturing miniature devices, especially when considering utilizing multiscale sheet metal hydroforming processes. One of the critical considerations during the design process is the burst pressure for the sheet metal which is a limiting factor for potential hydroforming operation...

The demand for miniature devices has increased the need for utilizing multi-scale hydroforming processes. Qualities in hydroformed parts such as reduced internal stresses and more homogeneous stress distributions compared to stamp formed parts result in reduced part failures. In addition, there is less material waste, high dimensional accuracy and...

In this study, the relationship between surface topography and strain was established for annealed 0.2 mm thick AISI 304 stainless steel sheet that had been hydroformed. The effect of the die diameter on the surface topography was also examined. Sheets were bulged using stepwise application of hydraulic pressure; forcing the sheet metal through 5 m...

A stamp forming die whose flexible blank holder was designed using finite element analysis was built. The tooling also included active draw beads, local wrinkling sensors, and local force transducers. Wrinkling was controlled using a PID feedback loop and blank holder force. Local forces in the tooling were also controlled using blank holder forces...

Force-based closed-loop control of stamp forming processes have in the past been investigated in order to improve the formability of sheet metal when forming automotive body panels. Previous researchers have controlled local forces and wrinkling using active draw beads and variable blank holder forces. However, it has been recognized that strain-ba...

Research of the microtube hydroforming (MTHF) process is being investigated for potential medical and fuel cell applications. This is largely due to the fact that at the macroscale the tube hydroforming (THF) process, like most metal forming processes, has realized many advantages, especially when comparing products made using traditional machining...

A stamp forming die, whose flexible blank holder was designed using FEA, was built. A closed-loop control system was used to control local punch forces and wrinkling by controlling both blank holder forces and draw bead penetration. The controllers for the draw beads featured an advanced PID controller with a Smith Predictor and Kalman Filter. A Ba...

Producing fuel cells bipolar plates and other devices such as microscale heat exchangers for electronics requires both macroscale and microscale forming processes. At the macroscale, typically, mechanical properties of sheet metal are determined by performing tensile tests. In addition, it has long been recognized that bi-axial tension tests, dome...

Producing fuel cells bipolar plates and other devices such as microscale heat exchangers for electronics requires both macroscale and microscale forming processes. At the macroscale, typically, mechanical properties of sheet metal are determined by performing tensile tests. In addition, it has long been recognized that bi-axial tension tests, dome...

Meso- and microscale sheet metal forming represents new and attractive solutions to many manufacturing problems for product miniaturization. Larger organizations are utilizing commercially available microscale digital image correlation systems to measure the strains on these scales. The cost of these systems is preventing smaller research and devel...

This paper considers the Bauschinger effect on cold finished, mild steel that had been subjected to friction stir processing. Four-point bend tests were performed on material specimens in a forward direction to 2% of true strain, followed by reverse bending to 4% of true strain. Strain gauges were mounted to the specimens to measure strain while th...

Micro and multiscale sheet metal forming processes represent new and attractive solutions to many manufacturing problems. However, evaluating the strains in these products is a difficult endeavor. Larger organizations are utilizing commercially available microscale digital image correlation systems to measure the strains in microscale parts or on m...

The research presented explores the relation between strain, surface roughness, and changing grain structure for annealed 0.2 mm thick AISI 304 stainless steel that has been hydroformed using 5 and 11 mm diameter circular open dies. The thickness strains at the pole of the bulge resulting from open die hydroforming were compared to analytically det...

The tube hydroforming (THF) process is a metal forming process that uses a pressurized fluid as the forming mechanism. Recently, this process has increased in popularity in the automotive industry as a method to reduce the number of required components and consolidate parts which can substantially reduce the overall automobile weight. This reductio...

A flexible blankholder for panel forming tooling was designed using finite element analysis. Once the appropriate thickness of the blankholder was determined, a study was performed in order to evaluate the locations of hydraulic cylinders for applying blankholding forces. The critical consideration for the studies was the ability to minimize wrinkl...

This study examines the robustness of stamp forming tooling. An oval pan was formed using tooling that included a flexible blank holder, active draw beads, and closed-loop control of both wrinkling and local punch forces. The results were compared to open-loop tests using the same tooling and earlier work that utilized tooling that produced similar...

Hydroforming at the macro scale offers the opportunity to create products that have superior mechanical properties and intricate complex geometries. Micro tube hydroforming is a process that is gaining popularity for similar reasons. At the same time, due to the physical size of the operations, there are many challenges including working with extre...

Microscale sheet metal forming represents a new and attractive solution to many manufacturing problems. Larger organizations are utilizing commercially available microscale digital image correlation systems to measure the strains on the microscale. The cost of these systems is preventing smaller research and development organizations from entering...

This paper describes the development and implementation of closed-loop control for oval stamp forming tooling using Matlab®’s Simulink® and the dSPACE® ControlDesk®. A traditional PID controller was used for the blank holder pressure and an advanced controller utilizing fuzzy logic combining a Linear Quadratic Gauss controller and a Bang-Bang contr...

This paper describes the development and implementation of closed-loop control for oval stamp forming tooling using MATLAB ® ’s SIMULINK ® and the d SPACE® CONTROLDESK ® . A traditional PID controller was used for the blank holder pressure and an advanced controller utilizing fuzzy logic combining a linear quadratic gauss controller and a bang–bang...

This paper presents a case study for inventory management for an oilfield equipment company. The management encounters the problem of deciding which parts to manufacture in-house and which ones to subcontract. A decision support system (DSS) is developed which ranks component parts by integrating multi-criteria classification methods considering bo...

Research of the micro tube hydroforming (MTHF) process is being investigated for potential medical and fuel cell applications. This is largely due to the fact that at the macro scale the tube hydroforming (THF) process, like most metal forming processes has realized many advantages. Unfortunately, large forces and high pressures are required to for...

This paper considers the Bauschinger effect on workpieces subjected to friction stir processing. Cold finished, mild steel was selected as the base material for this study. Four-point bend tests were performed on material specimens in a forward direction to 2% of true strain, followed by reverse bending by 4% of true strain or until failure. Strain...

This paper develops strain models based upon FEA simulations for an oval pan. The relationships for strain are at locations close to potential sites for embedded sensors including where the maximum plane strains occur. The models use draw bead position, blank holder force, and draw depth as input parameters. The model may be used for determining dr...

This paper describes the development and implementation of closed-loop control for an oval stamp forming die using Matlab® ’s Simulink® and the dSPACE® ControlDesk® . A traditional PID controller was used for the blank holder pressure and an advanced controller utilizing fuzzy logic combining a Linear Quadratic Gauss controller and a Bang-Bang cont...

The development of micro-electromechanical systems (MEMS) and micro-system technologies (MST) has increased the need for a better understanding of new micro scale manufacturing processes. Recent research has focused on creating new processes that manufacture better quality and low cost products. The use of micro metal forming processes presents exc...

An experimental evaluation of the strains in an oval stamp forming die is presented. The die design included a flexible blank holder and active draw beads. The die was instrumented with local punch force and wrinkle sensors and control systems were developed in order to follow local punch force and wrinkle trajectories. Strains were measured after...

An experimental evaluation of the strains in an oval stamp forming die is presented. The die design included a flexible blank holder and active draw beads. The die was instrumented with local punch force and wrinkle sensors. Control systems were developed in order to follow local punch force and wrinkle trajectories. Strains were measured after pan...

This paper compares the annual energy operating expenses for a typical combined heat and power (CHP) plant operation using nontraditional fuels with natural gas fired systems. The rationale for choosing to use fuels other than natural gas is because of availability of the fuel or the desire to reduce green house gas emissions. Specifically, we will...

In this research, a Manufacturing Information System (MIS) is developed for shop floor control and performance evaluation in discrete parts manufacturing industries. A relational database is designed first to organize manufacturing and quality data obtained from the workstations on the shop floor. The data tables and relations needed for database m...

An experimental evaluation of the robustness of an oval stamp forming die with a flexible binder designed using finite element modeling was performed using aluminum sheet metal as blanks. A systematic approach was used to determine the operational envelop of the die. The study indicates that a die with a flexible binder is significantly more robust...

A stamp forming die, whose flexible blank holder was designed using FEA, was built. Tests were performed to evaluate the robustness of the die once closed-loop control was implemented. These results were compared to the results of open-loop tests presented earlier. The closed-loop tests were designed to determine the die and control system’s abilit...

An experimental investigation into punch forces during a sheet metal stamping operation was performed for a sheet metal stamping die with a flexible blankholder and adjustable drawbeads. Tests were performed for various combinations of blankholder force and drawbead positions. Punch forces were measured using an instrumented punch and wrinkling in...

A flexible blankholder with a thickness designed by finite element analysis is used in a simulation study to minimize wrinkle development in an oblong symmetric panel. The location of six hydraulic blank holder cylinders and the different cylinder forces are used to determine the best blankholding scheme to hold wrinkles to a minimum. The study has...

Thesis (Ph.D.)--Michigan Technological University, 2006. Includes bibliographical references.

A theoretical investigation is described in which Finite Element Analysis is used to optimize the thickness of a flexible blankholder in the sheet metal forming process. Drawing of symmetric aluminum panels was simulated with different blankholder thickness and hydraulic blankholding cylinder positions. Initial simulations were compared with experi...