9396
The Vickers hardness increases gradually from 300 to 400 HV for the base metal to ∼1000 HV for the top layer of the Ti alloy , and the compressive strength of the Ti alloy reaches 1.92 GPa at a 1.5 L/min nitrogen flow rate .
 machanical property: Vickers hardness; material: base metal; process parameter: layer; material: Ti alloy; machanical property: compressive strength; material: Ti alloy; machanical property: GPa; process parameter: nitrogen flow rate
Given options, please tell me the categories of all the listed entity words.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} 
 Entities: Vickers hardness, base metal, layer, Ti alloy, compressive strength, Ti alloy, GPa, nitrogen flow rate 
Answer:
 machanical property: Vickers hardness; material: base metal; process parameter: layer; material: Ti alloy; machanical property: compressive strength; material: Ti alloy; machanical property: GPa; process parameter: nitrogen flow rate