This video demonstrates the use of a halogen line heater to focus infrared radiation into a linear pattern, selectively heating a specific area of a zinc plate.
Zinc, with a melting point of approximately 419.5°C, melts in the irradiated zone while the non-irradiated areas remain solid despite thermal conduction.
Please check the following site for more information.
Related page:
Line-Focused Infrared Heating | Localized Melting of a Tin Plate 
Line-Focused Infrared Heating | Localized Melting of a Lead Plate 
Melting of Zinc by High-Temperature Infrared Heating 
Melting Aluminum Plate with Halogen Line Heater 
Precision Melting of Chocolate with Infrared Localized Heating 
Melting of Tin by High-Temperature Infrared Heating 
Localized Infrared Heating and Melting of Polyurethane Tube Ends 
Melting of Zinc plate on a silicon wafer