Engineering topics

Lamikiz, A

Publications and source records attributed to Lamikiz, A.

4 records

DOE OSTI2011

Milling of Sand Blocks to Make Casting Moulds

In this paper a full procedure to make moulds in sand for direct casting of metallic parts is presented. The technology aims at unique pieces or art pieces, where only one prototype or components is required, but lead times are much reduced. The key of the procedure is to achieve enough tool life when milling with carbide tools, avoiding the risk of sand destruction or damage.The use of inverse techniques is a common input due to the industrial sectors where the direct milling is interesting. Two examples of moulds are presented, evaluating times and costs. A special study of tool wear is also presented.

36 MATERIALS SCIENCE↗

DOE OSTI2011

Friction Drilling of Stainless Steels Pipes

This work describes the experimental study of the friction drilling process in stainless steel by means of an optimization of the machining conditions. For such purpose austenitic stainless steel with different thicknesses were analyzed through controlled tests at different rotation speeds and feed rates. On one hand, the torque and the thrust force were computed and monitorized. On the other hand, the dimensional tolerances of the holes were evaluated, mainly the accuracy of the hole diameter and the burr thickness at different depths. Another topic of interest inherent to this special technique is the temperature level reached during the friction process which is crucial when it comes to development of microstructural transformations.

36 MATERIALS SCIENCE↗

DOE OSTI2011

Influence Of The Laser Cladding Strategies On The Mechanical Properties Of Inconel 718

This work presents different experimental results of the mechanical properties of Inconel registered 718 test parts built-up by laser cladding. Recently, turbine manufacturers for aeronautical sector have presented high interest on laser cladding processes. This process allows building fully functional structures on superalloys, such as Inconel registered 718, with high flexibility on complex shapes. However, there is limited data on mechanical properties of the laser cladding structures. Moreover, the available data do not include the influence of process parameters and laser cladding strategies. Therefore, a complete study of the influence of the laser cladding parameters and mainly, the variation of the tensile strength with the laser cladding strategy is presented. The results show that there is a high directionality of mechanical properties, depending on the strategies of laser cladding process. In other words, the test parts show a fiber -like structure that should be considered on the laser cladding strategy selection.

36 MATERIALS SCIENCE↗

DOE OSTI2011

Laser Hardening Prediction Tool Based On a Solid State Transformations Numerical Model

This paper presents a tool to predict hardening layer in selective laser hardening processes where laser beam heats the part locally while the bulk acts as a heat sink.The tool to predict accurately the temperature field in the workpiece is a numerical model that combines a three dimensional transient numerical solution for heating where is possible to introduce different laser sources. The thermal field was modeled using a kinetic model based on Johnson-Mehl-Avrami equation. Considering this equation, an experimental adjustment of transformation parameters was carried out to get the heating transformation diagrams (CHT). With the temperature field and CHT diagrams the model predicts the percentage of base material converted into austenite. These two parameters are used as first step to estimate the depth of hardened layer in the part.The model has been adjusted and validated with experimental data for DIN 1.2379, cold work tool steel typically used in mold and die making industry. This steel presents solid state diffusive transformations at relative low temperature. These transformations must be considered in order to get good accuracy of temperature field prediction during heating phase. For model validation, surface temperature measured by pyrometry, thermal field as well as the hardened layer obtained from metallographic study, were compared with the model data showing a good adjustment.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗