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A small amount of Ti alloy was melted when the first layer of Al alloy was deposited due to the low heat input .
 material: Ti alloy; concept or principle: melted; process parameter: layer; material: Al alloy; concept or principle: heat
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: Ti alloy; concept or principle: melted; process parameter: layer; material: Al alloy; concept or principle: heat