{"id":23658,"date":"2024-07-23T08:04:35","date_gmt":"2024-07-23T06:04:35","guid":{"rendered":"https:\/\/www.linseis.com\/determination-of-conversion-temperatures-of-steel-samples-with-the-help-of-laser-speckles\/"},"modified":"2024-08-12T13:22:11","modified_gmt":"2024-08-12T11:22:11","slug":"determination-of-conversion-temperatures-of-steel-samples-with-the-help-of-laser-speckles","status":"publish","type":"post","link":"https:\/\/www.linseis.com\/en\/news\/determination-of-conversion-temperatures-of-steel-samples-with-the-help-of-laser-speckles\/","title":{"rendered":"Determination of conversion temperatures of steel samples with the help of laser speckles"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"23658\" class=\"elementor elementor-23658 elementor-16629\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9eb8745 e-flex e-con-boxed e-con e-parent\" data-id=\"9eb8745\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ffaef65 elementor-widget elementor-widget-text-editor\" data-id=\"ffaef65\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Measuring the temperature dependent change in length can be used to determine the temperature at which a structural transformation takes place in steel samples. With the laser speckles method, the sample surface is illuminated a laser and observed from above with a camera. At the same time, the sample is heated with the help of an induction coil. To filter the heat radiation and the light that emitted from glowing sample, a blue laser is used and appropriate filters are attached in front of the camera.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1089cc3 elementor-widget elementor-widget-heading\" data-id=\"1089cc3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Schematic of the setup<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-194a95e elementor-widget elementor-widget-image\" data-id=\"194a95e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"300\" height=\"268\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Grafik-1-300x268-1.png\" class=\"attachment-large size-large wp-image-16633\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d3857b9 elementor-widget elementor-widget-heading\" data-id=\"d3857b9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Measurment<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cfa7bd8 elementor-widget elementor-widget-text-editor\" data-id=\"cfa7bd8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>During the measurement, the sample is heated inductively and at the same time the speckle patterns generated by the laser are observed with the camera. Depending on the speed of the measurement, up to 50 frames per second can be recorded.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a9ea203 elementor-widget elementor-widget-heading\" data-id=\"a9ea203\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Evaluation<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f296a60 elementor-widget elementor-widget-text-editor\" data-id=\"f296a60\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\tThe camera generates sequences of images like this:\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-590e1d7 elementor-widget elementor-widget-text-editor\" data-id=\"590e1d7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Since the speckles are mainly generated by interference effects on surface unevenness on the sample, the movement of the speckles on the surface can be measured by tracking user-definable areas.<\/p>\n<p>A special algorithm based on a cross-correlation of two consecutive images determines the movement of the areas in the image.<\/p>\n<p>The size and position of the areas is user-definable. Additional to tracking the total distance of the areas the tracking direction can be constrained to vertical and horizontal direction.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-721ede4 elementor-widget elementor-widget-image\" data-id=\"721ede4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"300\" height=\"162\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Grafik-2-300x162-1.png\" class=\"attachment-medium_large size-medium_large wp-image-16640\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-29c2b60 elementor-widget elementor-widget-text-editor\" data-id=\"29c2b60\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>This allows for measuring anisotropic expansion behavior of samples. The measured expansion is independent from pushrod expansion.<br \/>\nA big advantage compared to the LVDT measurement is, that the temperature over the small area recorded by the camera is distributed much more homogeneously than over the entire sample length. So microstructural transitions can be seen more clearly than with the LVDT.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1ac67eb elementor-widget elementor-widget-heading\" data-id=\"1ac67eb\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Comparison to push rod measurment<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-64ce74b elementor-widget elementor-widget-image\" data-id=\"64ce74b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"300\" height=\"169\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Grafik-3-300x169-1.png\" class=\"attachment-medium_large size-medium_large wp-image-16650\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2e193bf elementor-widget elementor-widget-text-editor\" data-id=\"2e193bf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>This image shows the measuring signal of the LVDT in X-direction (black) and the measuring signal of the speckles-camera in Y-direction (blue). Start and finish points of phase transitions can be observed more clearly.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7396e18 elementor-widget elementor-widget-heading\" data-id=\"7396e18\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Measuring a tensile sample<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0b7959b elementor-widget elementor-widget-image\" data-id=\"0b7959b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"262\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Grafik-4-300x262-1.png\" class=\"attachment-large size-large wp-image-16660\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c545a36 elementor-widget elementor-widget-image\" data-id=\"c545a36\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"127\" src=\"https:\/\/www.linseis.com\/wp-content\/uploads\/2024\/07\/Messung-2-300x127-1.png\" class=\"attachment-large size-large wp-image-16667\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5c33d3b elementor-widget elementor-widget-text-editor\" data-id=\"5c33d3b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>For tensile samples, the expansion measurement can be done by defining several independent regions. It is possible to track these regions to measure the expansion between these points in axial direction.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3ad7e18 elementor-widget elementor-widget-spacer\" data-id=\"3ad7e18\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>By measuring the temperature-dependent change in length, the temperature at which a microstructural transformation takes place in steel samples can be determined.<\/p>\n","protected":false},"author":3,"featured_media":16623,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[109],"tags":[],"class_list":["post-23658","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/23658","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/comments?post=23658"}],"version-history":[{"count":0,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/23658\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media\/16623"}],"wp:attachment":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media?parent=23658"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/categories?post=23658"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/tags?post=23658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}